chore(package): update webpack to version 2.3.1

Closes #68

https://greenkeeper.io/

Author: greenkeeper[bot]

package.json

@@ -108,7 +108,7 @@
     "typedoc": "^0.5.3",
     "typescript": "~2.1.5",
     "url-loader": "^0.5.7",
-    "webpack": "2.2.1",
+    "webpack": "2.3.1",
     "webpack-dashboard": "0.3.0",
     "webpack-dev-middleware": "1.10.0",
     "webpack-dev-server": "2.3.0",