chore(package): update rollup-plugin-sourcemaps to version 0.6.2

Closes #64

Author: greenkeeper[bot]

package.json

@@ -92,7 +92,7 @@
     "rollup": "^0.67.4",
     "rollup-plugin-commonjs": "^9.2.2",
     "rollup-plugin-node-resolve": "^3.4.0",
-    "rollup-plugin-sourcemaps": "^0.4.2",
+    "rollup-plugin-sourcemaps": "^0.6.2",
     "rollup-plugin-uglify": "^3.0.0",
     "run-sequence": "^2.2.1",
     "rxjs": "^6.3.3",