diff --git a/.travis.yml b/.travis.yml
index b8b97f75f..52f7d4e7c 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -6,7 +6,6 @@ node_js:
   - "9"
   - "8"
   - "6"
-  - "4"
 before_install:
   # from https://github.com/travis-ci/travis-ci/issues/3225#issuecomment-177592725
   # and also from https://github.com/travis-ci/travis-ci/issues/3225#issuecomment-200965782
diff --git a/package-lock.json b/package-lock.json
index 90e4d74f0..d1bf94899 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,6 +1,6 @@
 {
   "name": "less",
-  "version": "3.0.1",
+  "version": "3.0.2",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
@@ -237,8 +237,7 @@
     "asn1": {
       "version": "0.2.3",
       "resolved": "https://registry.npmjs.org/asn1/-/asn1-0.2.3.tgz",
-      "integrity": "sha1-2sh4dxPJlmhJ/IGAd36+nB3fO4Y=",
-      "dev": true
+      "integrity": "sha1-2sh4dxPJlmhJ/IGAd36+nB3fO4Y="
     },
     "asn1.js": {
       "version": "4.9.1",
@@ -263,8 +262,7 @@
     "assert-plus": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/assert-plus/-/assert-plus-1.0.0.tgz",
-      "integrity": "sha1-8S4PPF13sLHN2RRpQuTpbB5N1SU=",
-      "dev": true
+      "integrity": "sha1-8S4PPF13sLHN2RRpQuTpbB5N1SU="
     },
     "astw": {
       "version": "2.2.0",
@@ -290,20 +288,17 @@
     "asynckit": {
       "version": "0.4.0",
       "resolved": "https://registry.npmjs.org/asynckit/-/asynckit-0.4.0.tgz",
-      "integrity": "sha1-x57Zf380y48robyXkLzDZkdLS3k=",
-      "dev": true
+      "integrity": "sha1-x57Zf380y48robyXkLzDZkdLS3k="
     },
     "aws-sign2": {
       "version": "0.7.0",
       "resolved": "https://registry.npmjs.org/aws-sign2/-/aws-sign2-0.7.0.tgz",
-      "integrity": "sha1-tG6JCTSpWR8tL2+G1+ap8bP+dqg=",
-      "dev": true
+      "integrity": "sha1-tG6JCTSpWR8tL2+G1+ap8bP+dqg="
     },
     "aws4": {
       "version": "1.6.0",
       "resolved": "https://registry.npmjs.org/aws4/-/aws4-1.6.0.tgz",
-      "integrity": "sha1-g+9cqGCysy5KDe7e6MdxudtXRx4=",
-      "dev": true
+      "integrity": "sha1-g+9cqGCysy5KDe7e6MdxudtXRx4="
     },
     "babel-code-frame": {
       "version": "6.26.0",
@@ -347,7 +342,6 @@
       "version": "1.0.1",
       "resolved": "https://registry.npmjs.org/bcrypt-pbkdf/-/bcrypt-pbkdf-1.0.1.tgz",
       "integrity": "sha1-Y7xdy2EzG5K8Bf1SiVPDNGKgb40=",
-      "dev": true,
       "optional": true,
       "requires": {
         "tweetnacl": "0.14.5"
@@ -369,7 +363,6 @@
       "version": "4.3.1",
       "resolved": "https://registry.npmjs.org/boom/-/boom-4.3.1.tgz",
       "integrity": "sha1-T4owBctKfjiJ90kDD9JbluAdLjE=",
-      "dev": true,
       "requires": {
         "hoek": "4.2.1"
       }
@@ -698,8 +691,7 @@
     "caseless": {
       "version": "0.12.0",
       "resolved": "https://registry.npmjs.org/caseless/-/caseless-0.12.0.tgz",
-      "integrity": "sha1-G2gcIf+EAzyCZUMJBolCDRhxUdw=",
-      "dev": true
+      "integrity": "sha1-G2gcIf+EAzyCZUMJBolCDRhxUdw="
     },
     "center-align": {
       "version": "0.1.3",
@@ -807,8 +799,7 @@
     "co": {
       "version": "4.6.0",
       "resolved": "https://registry.npmjs.org/co/-/co-4.6.0.tgz",
-      "integrity": "sha1-bqa989hTrlTMuOR7+gvz+QMfsYQ=",
-      "dev": true
+      "integrity": "sha1-bqa989hTrlTMuOR7+gvz+QMfsYQ="
     },
     "code-point-at": {
       "version": "1.1.0",
@@ -838,13 +829,20 @@
         "inline-source-map": "0.6.2",
         "lodash.memoize": "3.0.4",
         "source-map": "0.5.7"
+      },
+      "dependencies": {
+        "source-map": {
+          "version": "0.5.7",
+          "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.5.7.tgz",
+          "integrity": "sha1-igOdLRAh0i0eoUyA2OpGi6LvP8w=",
+          "dev": true
+        }
       }
     },
     "combined-stream": {
       "version": "1.0.6",
       "resolved": "https://registry.npmjs.org/combined-stream/-/combined-stream-1.0.6.tgz",
       "integrity": "sha1-cj599ugBrFYTETp+RFqbactjKBg=",
-      "dev": true,
       "requires": {
         "delayed-stream": "1.0.0"
       }
@@ -939,8 +937,7 @@
     "core-util-is": {
       "version": "1.0.2",
       "resolved": "https://registry.npmjs.org/core-util-is/-/core-util-is-1.0.2.tgz",
-      "integrity": "sha1-tf1UIgqivFq1eqtxQMlAdUUDwac=",
-      "dev": true
+      "integrity": "sha1-tf1UIgqivFq1eqtxQMlAdUUDwac="
     },
     "create-ecdh": {
       "version": "4.0.0",
@@ -982,7 +979,6 @@
       "version": "3.1.2",
       "resolved": "https://registry.npmjs.org/cryptiles/-/cryptiles-3.1.2.tgz",
       "integrity": "sha1-qJ+7Ig9c4l7FboxKqKT9e1sNKf4=",
-      "dev": true,
       "requires": {
         "boom": "5.2.0"
       },
@@ -991,7 +987,6 @@
           "version": "5.2.0",
           "resolved": "https://registry.npmjs.org/boom/-/boom-5.2.0.tgz",
           "integrity": "sha512-Z5BTk6ZRe4tXXQlkqftmsAUANpXmuwlsF5Oov8ThoMbQRzdGTA1ngYRW160GexgOgjsFOKJz0LYhoNi+2AMBUw==",
-          "dev": true,
           "requires": {
             "hoek": "4.2.1"
           }
@@ -1038,7 +1033,6 @@
       "version": "1.14.1",
       "resolved": "https://registry.npmjs.org/dashdash/-/dashdash-1.14.1.tgz",
       "integrity": "sha1-hTz6D3y+L+1d4gMmuN1YEDX24vA=",
-      "dev": true,
       "requires": {
         "assert-plus": "1.0.0"
       }
@@ -1109,8 +1103,7 @@
     "delayed-stream": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/delayed-stream/-/delayed-stream-1.0.0.tgz",
-      "integrity": "sha1-3zrhmayt+31ECqrgsp4icrJOxhk=",
-      "dev": true
+      "integrity": "sha1-3zrhmayt+31ECqrgsp4icrJOxhk="
     },
     "depd": {
       "version": "1.1.1",
@@ -1202,7 +1195,6 @@
       "version": "0.1.1",
       "resolved": "https://registry.npmjs.org/ecc-jsbn/-/ecc-jsbn-0.1.1.tgz",
       "integrity": "sha1-D8c6ntXw1Tw4GTOYUj735UN3dQU=",
-      "dev": true,
       "optional": true,
       "requires": {
         "jsbn": "0.1.1"
@@ -1593,8 +1585,7 @@
     "extend": {
       "version": "3.0.1",
       "resolved": "https://registry.npmjs.org/extend/-/extend-3.0.1.tgz",
-      "integrity": "sha1-p1Xqe8Gt/MWjHOfnYtuq3F5jZEQ=",
-      "dev": true
+      "integrity": "sha1-p1Xqe8Gt/MWjHOfnYtuq3F5jZEQ="
     },
     "extglob": {
       "version": "0.3.2",
@@ -1657,20 +1648,17 @@
     "extsprintf": {
       "version": "1.3.0",
       "resolved": "https://registry.npmjs.org/extsprintf/-/extsprintf-1.3.0.tgz",
-      "integrity": "sha1-lpGEQOMEGnpBT4xS48V06zw+HgU=",
-      "dev": true
+      "integrity": "sha1-lpGEQOMEGnpBT4xS48V06zw+HgU="
     },
     "fast-deep-equal": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/fast-deep-equal/-/fast-deep-equal-1.0.0.tgz",
-      "integrity": "sha1-liVqO8l1WV6zbYLpkp0GDYk0Of8=",
-      "dev": true
+      "integrity": "sha1-liVqO8l1WV6zbYLpkp0GDYk0Of8="
     },
     "fast-json-stable-stringify": {
       "version": "2.0.0",
       "resolved": "https://registry.npmjs.org/fast-json-stable-stringify/-/fast-json-stable-stringify-2.0.0.tgz",
-      "integrity": "sha1-1RQsDK7msRifh9OnYREGT4bIu/I=",
-      "dev": true
+      "integrity": "sha1-1RQsDK7msRifh9OnYREGT4bIu/I="
     },
     "fast-levenshtein": {
       "version": "2.0.6",
@@ -1843,14 +1831,12 @@
     "forever-agent": {
       "version": "0.6.1",
       "resolved": "https://registry.npmjs.org/forever-agent/-/forever-agent-0.6.1.tgz",
-      "integrity": "sha1-+8cfDEGt6zf5bFd60e1C2P2sypE=",
-      "dev": true
+      "integrity": "sha1-+8cfDEGt6zf5bFd60e1C2P2sypE="
     },
     "form-data": {
       "version": "2.3.2",
       "resolved": "https://registry.npmjs.org/form-data/-/form-data-2.3.2.tgz",
       "integrity": "sha1-SXBJi+YEwgwAXU9cI67NIda0kJk=",
-      "dev": true,
       "requires": {
         "asynckit": "0.4.0",
         "combined-stream": "1.0.6",
@@ -2316,7 +2302,8 @@
         "jsbn": {
           "version": "0.1.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "json-schema": {
           "version": "0.2.3",
@@ -2815,7 +2802,6 @@
       "version": "0.1.7",
       "resolved": "https://registry.npmjs.org/getpass/-/getpass-0.1.7.tgz",
       "integrity": "sha1-Xv+OPmhNVprkyysSgmBOi6YhSfo=",
-      "dev": true,
       "requires": {
         "assert-plus": "1.0.0"
       }
@@ -3067,6 +3053,14 @@
       "requires": {
         "chalk": "1.1.3",
         "source-map": "0.5.7"
+      },
+      "dependencies": {
+        "source-map": {
+          "version": "0.5.7",
+          "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.5.7.tgz",
+          "integrity": "sha1-igOdLRAh0i0eoUyA2OpGi6LvP8w=",
+          "dev": true
+        }
       }
     },
     "grunt-contrib-connect": {
@@ -3313,14 +3307,12 @@
     "har-schema": {
       "version": "2.0.0",
       "resolved": "https://registry.npmjs.org/har-schema/-/har-schema-2.0.0.tgz",
-      "integrity": "sha1-qUwiJOvKwEeCoNkDVSHyRzW37JI=",
-      "dev": true
+      "integrity": "sha1-qUwiJOvKwEeCoNkDVSHyRzW37JI="
     },
     "har-validator": {
       "version": "5.0.3",
       "resolved": "https://registry.npmjs.org/har-validator/-/har-validator-5.0.3.tgz",
       "integrity": "sha1-ukAsJmGU8VlW7xXg/PJCmT9qff0=",
-      "dev": true,
       "requires": {
         "ajv": "5.5.2",
         "har-schema": "2.0.0"
@@ -3330,7 +3322,6 @@
           "version": "5.5.2",
           "resolved": "https://registry.npmjs.org/ajv/-/ajv-5.5.2.tgz",
           "integrity": "sha1-c7Xuyj+rZT49P5Qis0GtQiBdyWU=",
-          "dev": true,
           "requires": {
             "co": "4.6.0",
             "fast-deep-equal": "1.0.0",
@@ -3391,7 +3382,6 @@
       "version": "6.0.2",
       "resolved": "https://registry.npmjs.org/hawk/-/hawk-6.0.2.tgz",
       "integrity": "sha512-miowhl2+U7Qle4vdLqDdPt9m09K6yZhkLDTWGoUiUzrQCn+mHHSmfJgAyGaLRZbPmTqfFFjRV1QWCW0VWUJBbQ==",
-      "dev": true,
       "requires": {
         "boom": "4.3.1",
         "cryptiles": "3.1.2",
@@ -3413,8 +3403,7 @@
     "hoek": {
       "version": "4.2.1",
       "resolved": "https://registry.npmjs.org/hoek/-/hoek-4.2.1.tgz",
-      "integrity": "sha512-QLg82fGkfnJ/4iy1xZ81/9SIJiq1NGFUMGs6ParyjBZr6jW2Ufj/snDqTHixNlHdPNwN2RLVD0Pi3igeK9+JfA==",
-      "dev": true
+      "integrity": "sha512-QLg82fGkfnJ/4iy1xZ81/9SIJiq1NGFUMGs6ParyjBZr6jW2Ufj/snDqTHixNlHdPNwN2RLVD0Pi3igeK9+JfA=="
     },
     "hooker": {
       "version": "0.2.3",
@@ -3450,7 +3439,6 @@
       "version": "1.2.0",
       "resolved": "https://registry.npmjs.org/http-signature/-/http-signature-1.2.0.tgz",
       "integrity": "sha1-muzZJRFHcvPZW2WmCruPfBj7rOE=",
-      "dev": true,
       "requires": {
         "assert-plus": "1.0.0",
         "jsprim": "1.4.1",
@@ -3552,6 +3540,14 @@
       "dev": true,
       "requires": {
         "source-map": "0.5.7"
+      },
+      "dependencies": {
+        "source-map": {
+          "version": "0.5.7",
+          "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.5.7.tgz",
+          "integrity": "sha1-igOdLRAh0i0eoUyA2OpGi6LvP8w=",
+          "dev": true
+        }
       }
     },
     "inquirer": {
@@ -3770,8 +3766,7 @@
     "is-typedarray": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/is-typedarray/-/is-typedarray-1.0.0.tgz",
-      "integrity": "sha1-5HnICFjfDBsR3dppQPlgEfzaSpo=",
-      "dev": true
+      "integrity": "sha1-5HnICFjfDBsR3dppQPlgEfzaSpo="
     },
     "is-utf8": {
       "version": "0.2.1",
@@ -3803,8 +3798,7 @@
     "isstream": {
       "version": "0.1.2",
       "resolved": "https://registry.npmjs.org/isstream/-/isstream-0.1.2.tgz",
-      "integrity": "sha1-R+Y/evVa+m+S4VAOaQ64uFKcCZo=",
-      "dev": true
+      "integrity": "sha1-R+Y/evVa+m+S4VAOaQ64uFKcCZo="
     },
     "jasmine-core": {
       "version": "2.4.1",
@@ -3838,20 +3832,17 @@
       "version": "0.1.1",
       "resolved": "https://registry.npmjs.org/jsbn/-/jsbn-0.1.1.tgz",
       "integrity": "sha1-peZUwuWi3rXyAdls77yoDA7y9RM=",
-      "dev": true,
       "optional": true
     },
     "json-schema": {
       "version": "0.2.3",
       "resolved": "https://registry.npmjs.org/json-schema/-/json-schema-0.2.3.tgz",
-      "integrity": "sha1-tIDIkuWaLwWVTOcnvT8qTogvnhM=",
-      "dev": true
+      "integrity": "sha1-tIDIkuWaLwWVTOcnvT8qTogvnhM="
     },
     "json-schema-traverse": {
       "version": "0.3.1",
       "resolved": "https://registry.npmjs.org/json-schema-traverse/-/json-schema-traverse-0.3.1.tgz",
-      "integrity": "sha1-NJptRMU6Ud6JtAgFxdXlm0F9M0A=",
-      "dev": true
+      "integrity": "sha1-NJptRMU6Ud6JtAgFxdXlm0F9M0A="
     },
     "json-stable-stringify": {
       "version": "0.0.1",
@@ -3865,8 +3856,7 @@
     "json-stringify-safe": {
       "version": "5.0.1",
       "resolved": "https://registry.npmjs.org/json-stringify-safe/-/json-stringify-safe-5.0.1.tgz",
-      "integrity": "sha1-Epai1Y/UXxmg9s4B1lcB4sc1tus=",
-      "dev": true
+      "integrity": "sha1-Epai1Y/UXxmg9s4B1lcB4sc1tus="
     },
     "jsonfile": {
       "version": "2.4.0",
@@ -3899,7 +3889,6 @@
       "version": "1.4.1",
       "resolved": "https://registry.npmjs.org/jsprim/-/jsprim-1.4.1.tgz",
       "integrity": "sha1-MT5mvB5cwG5Di8G3SZwuXFastqI=",
-      "dev": true,
       "requires": {
         "assert-plus": "1.0.0",
         "extsprintf": "1.3.0",
@@ -4136,14 +4125,12 @@
     "mime-db": {
       "version": "1.30.0",
       "resolved": "https://registry.npmjs.org/mime-db/-/mime-db-1.30.0.tgz",
-      "integrity": "sha1-dMZD2i3Z1qRTmZY0ZbJtXKfXHwE=",
-      "dev": true
+      "integrity": "sha1-dMZD2i3Z1qRTmZY0ZbJtXKfXHwE="
     },
     "mime-types": {
       "version": "2.1.17",
       "resolved": "https://registry.npmjs.org/mime-types/-/mime-types-2.1.17.tgz",
       "integrity": "sha1-Cdejk/A+mVp5+K+Fe3Cp4KsWVXo=",
-      "dev": true,
       "requires": {
         "mime-db": "1.30.0"
       }
@@ -4298,8 +4285,7 @@
     "oauth-sign": {
       "version": "0.8.2",
       "resolved": "https://registry.npmjs.org/oauth-sign/-/oauth-sign-0.8.2.tgz",
-      "integrity": "sha1-Rqarfwrq2N6unsBWV4C31O/rnUM=",
-      "dev": true
+      "integrity": "sha1-Rqarfwrq2N6unsBWV4C31O/rnUM="
     },
     "object-assign": {
       "version": "4.1.1",
@@ -4846,8 +4832,7 @@
     "punycode": {
       "version": "1.4.1",
       "resolved": "https://registry.npmjs.org/punycode/-/punycode-1.4.1.tgz",
-      "integrity": "sha1-wNWmOycYgArY4esPpSachN1BhF4=",
-      "dev": true
+      "integrity": "sha1-wNWmOycYgArY4esPpSachN1BhF4="
     },
     "q": {
       "version": "1.4.1",
@@ -4858,8 +4843,7 @@
     "qs": {
       "version": "6.5.1",
       "resolved": "https://registry.npmjs.org/qs/-/qs-6.5.1.tgz",
-      "integrity": "sha512-eRzhrN1WSINYCDCbrz796z37LOe3m5tmW7RQf6oBntukAG1nmovJvhnwHHRMAfeoItc1m2Hk02WER2aQ/iqs+A==",
-      "dev": true
+      "integrity": "sha512-eRzhrN1WSINYCDCbrz796z37LOe3m5tmW7RQf6oBntukAG1nmovJvhnwHHRMAfeoItc1m2Hk02WER2aQ/iqs+A=="
     },
     "querystring": {
       "version": "0.2.0",
@@ -5067,7 +5051,6 @@
       "version": "2.83.0",
       "resolved": "https://registry.npmjs.org/request/-/request-2.83.0.tgz",
       "integrity": "sha512-lR3gD69osqm6EYLk9wB/G1W/laGWjzH90t1vEa2xuxHD5KUrSzp9pUSfTm+YC5Nxt2T8nMPEvKlhbQayU7bgFw==",
-      "dev": true,
       "requires": {
         "aws-sign2": "0.7.0",
         "aws4": "1.6.0",
@@ -5096,8 +5079,7 @@
         "performance-now": {
           "version": "2.1.0",
           "resolved": "https://registry.npmjs.org/performance-now/-/performance-now-2.1.0.tgz",
-          "integrity": "sha1-Ywn04OX6kT7BxpMHrjZLSzd8nns=",
-          "dev": true
+          "integrity": "sha1-Ywn04OX6kT7BxpMHrjZLSzd8nns="
         }
       }
     },
@@ -5200,8 +5182,7 @@
     "safe-buffer": {
       "version": "5.1.1",
       "resolved": "https://registry.npmjs.org/safe-buffer/-/safe-buffer-5.1.1.tgz",
-      "integrity": "sha512-kKvNJn6Mm93gAczWVJg7wH+wGYWNrDHdWvpUmHyEsgCtIwwo3bqPtV4tR5tuPaUhTOo/kvhVwd8XwwOllGYkbg==",
-      "dev": true
+      "integrity": "sha512-kKvNJn6Mm93gAczWVJg7wH+wGYWNrDHdWvpUmHyEsgCtIwwo3bqPtV4tR5tuPaUhTOo/kvhVwd8XwwOllGYkbg=="
     },
     "sauce-tunnel": {
       "version": "2.5.0",
@@ -5379,15 +5360,15 @@
       "version": "2.1.0",
       "resolved": "https://registry.npmjs.org/sntp/-/sntp-2.1.0.tgz",
       "integrity": "sha512-FL1b58BDrqS3A11lJ0zEdnJ3UOKqVxawAkF3k7F0CVN7VQ34aZrV+G8BZ1WC9ZL7NyrwsW0oviwsWDgRuVYtJg==",
-      "dev": true,
       "requires": {
         "hoek": "4.2.1"
       }
     },
     "source-map": {
-      "version": "0.5.7",
-      "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.5.7.tgz",
-      "integrity": "sha1-igOdLRAh0i0eoUyA2OpGi6LvP8w="
+      "version": "0.6.1",
+      "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.6.1.tgz",
+      "integrity": "sha512-UjgapumWlbMhkBgzT7Ykc5YXUT46F0iKu8SGXq0bcwP5dz/h0Plj6enJqjz1Zbq2l5WaqYnrVbwWOWMyF3F47g==",
+      "optional": true
     },
     "spdx-correct": {
       "version": "1.0.2",
@@ -5429,7 +5410,6 @@
       "version": "1.13.1",
       "resolved": "https://registry.npmjs.org/sshpk/-/sshpk-1.13.1.tgz",
       "integrity": "sha1-US322mKHFEMW3EwY/hzx2UBzm+M=",
-      "dev": true,
       "requires": {
         "asn1": "0.2.3",
         "assert-plus": "1.0.0",
@@ -5513,8 +5493,7 @@
     "stringstream": {
       "version": "0.0.5",
       "resolved": "https://registry.npmjs.org/stringstream/-/stringstream-0.0.5.tgz",
-      "integrity": "sha1-TkhM1N5aC7vuGORjB3EKioFiGHg=",
-      "dev": true
+      "integrity": "sha1-TkhM1N5aC7vuGORjB3EKioFiGHg="
     },
     "strip-ansi": {
       "version": "3.0.1",
@@ -5711,7 +5690,6 @@
       "version": "2.3.3",
       "resolved": "https://registry.npmjs.org/tough-cookie/-/tough-cookie-2.3.3.tgz",
       "integrity": "sha1-C2GKVWW23qkL80JdBNVe3EdadWE=",
-      "dev": true,
       "requires": {
         "punycode": "1.4.1"
       }
@@ -5738,7 +5716,6 @@
       "version": "0.6.0",
       "resolved": "https://registry.npmjs.org/tunnel-agent/-/tunnel-agent-0.6.0.tgz",
       "integrity": "sha1-J6XeoGs2sEoKmWZ3SykIaPD8QP0=",
-      "dev": true,
       "requires": {
         "safe-buffer": "5.1.1"
       }
@@ -5747,7 +5724,6 @@
       "version": "0.14.5",
       "resolved": "https://registry.npmjs.org/tweetnacl/-/tweetnacl-0.14.5.tgz",
       "integrity": "sha1-WuaBd/GS1EViadEIr6k/+HQ/T2Q=",
-      "dev": true,
       "optional": true
     },
     "type-check": {
@@ -5782,6 +5758,12 @@
           "resolved": "https://registry.npmjs.org/async/-/async-0.2.10.tgz",
           "integrity": "sha1-trvgsGdLnXGXCMo43owjfLUmw9E=",
           "dev": true
+        },
+        "source-map": {
+          "version": "0.5.7",
+          "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.5.7.tgz",
+          "integrity": "sha1-igOdLRAh0i0eoUyA2OpGi6LvP8w=",
+          "dev": true
         }
       }
     },
@@ -5880,8 +5862,7 @@
     "uuid": {
       "version": "3.2.1",
       "resolved": "https://registry.npmjs.org/uuid/-/uuid-3.2.1.tgz",
-      "integrity": "sha512-jZnMwlb9Iku/O3smGWvZhauCf6cvvpKi4BKRiliS3cxnI+Gz9j5MEpTz2UFuXiKPJocb7gnsLHwiS05ige5BEA==",
-      "dev": true
+      "integrity": "sha512-jZnMwlb9Iku/O3smGWvZhauCf6cvvpKi4BKRiliS3cxnI+Gz9j5MEpTz2UFuXiKPJocb7gnsLHwiS05ige5BEA=="
     },
     "validate-npm-package-license": {
       "version": "3.0.1",
@@ -5897,7 +5878,6 @@
       "version": "1.10.0",
       "resolved": "https://registry.npmjs.org/verror/-/verror-1.10.0.tgz",
       "integrity": "sha1-OhBcoXBTr1XW4nDB+CiGguGNpAA=",
-      "dev": true,
       "requires": {
         "assert-plus": "1.0.0",
         "core-util-is": "1.0.2",
diff --git a/package.json b/package.json
index de6eb6cac..75345ae92 100644
--- a/package.json
+++ b/package.json
@@ -47,7 +47,7 @@
     "mkdirp": "^0.5.0",
     "promise": "^7.1.1",
     "request": "^2.83.0",
-    "source-map": "^0.5.3"
+    "source-map": "~0.6.0"
   },
   "devDependencies": {
     "diff": "^3.2.0",