chore(package): update webpack to version 3.5.1

Closes #18

Author: greenkeeper[bot]

package.json

@@ -58,7 +58,7 @@
     "rimraf": "2.6.1",
     "style-loader": "^0.16.1",
     "surge": "^0.19.0",
-    "webpack": "^2.3.3",
+    "webpack": "^3.5.1",
     "webpack-dev-middleware": "^1.10.1",
     "webpack-hot-middleware": "^2.18.0",
     "webpack-md5-hash": "0.0.5"