Upgrade webpack to v2 and other deps (#8491)

* update to webpack2 and other deps

* fix linting

webpack/dev-server.js

@@ -4,8 +4,13 @@ const path = require('path');
 const express = require('express');
 const webpack = require('webpack');
 const config = require('./config');
+
+if (!process.env.NODE_ENV) {
+  process.env.NODE_ENV = JSON.parse(config.dev.env.NODE_ENV);
+}
+
 const proxyMiddleware = require('http-proxy-middleware');
-const webpackConfig = process.env.NODE_ENV === 'testing' ?
+const webpackConfig = process.env.NODE_ENV === 'test' ?
   require('./webpack.prod.conf') :
   require('./webpack.dev.conf');
 
@@ -41,7 +46,7 @@ Object.keys(proxyTable).forEach((context) => {
   if (typeof options === 'string') {
     options = { target: options };
   }
-  app.use(proxyMiddleware(context, options));
+  app.use(proxyMiddleware(options.filter || context, options));
 });
 
 // handle fallback for HTML5 history API