chore(package): update webpack to version 4.40.1

Closes #9

Author: greenkeeper[bot]

package.json

@@ -21,7 +21,7 @@
     "cz-conventional-changelog": "2.1.0",
     "semantic-release": "^15.0.1",
     "travis-deploy-once": "^5.0.1",
-    "webpack": "4.16.3",
+    "webpack": "4.40.1",
     "webpack-cli": "3.1.0"
   },
   "repository": {