Update webpack to the latest version 🚀 (#29)

Author: greenkeeper[bot]

package.json

@@ -12,7 +12,7 @@
     "coveralls": "2.x",
     "nyc": "10.2.0",
     "standard": "10.0.0",
-    "webpack": "^2.6.0"
+    "webpack": "^3.0.0"
   },
   "engines": {
     "node": ">= 6.0.0"