Use -p flag instead of explicitly adding plugins

Author: mjackson

website/package.json

@@ -4,7 +4,7 @@
   "private": true,
   "scripts": {
     "dev": "webpack-dev-server --inline",
-    "build": "npm run clean && webpack",
+    "build": "npm run clean && webpack -p",
     "clean": "rm -rf build",
     "start": "npm run build && pushstate-server build/"
   },

website/webpack.config.js

@@ -29,11 +29,7 @@ module.exports = {
       baseHref: PROD ? '//reacttraining.github.io/react-router/' : '/',
       template: 'index.html.ejs'
     })
-  ].concat(PROD ? [
-    new webpack.optimize.DedupePlugin(),
-    new webpack.optimize.OccurrenceOrderPlugin(),
-    new webpack.optimize.UglifyJsPlugin()
-  ] : []),
+  ],
 
   resolve: {
     alias: {