Dont use -p on webpack when declaring uglifyjs plugin

client/package.json

@@ -58,7 +58,7 @@
     "webpack-dev-server": "~1.12.1"
   },
   "scripts": {
-    "build": "webpack -p --config webpack.production.config.js",
+    "build": "webpack --config webpack.production.config.js",
     "start": "node server.js",
     "start-production": "NODE_ENV=production node server.js",
     "test": "jest",

client/webpack.production.config.js

@@ -73,7 +73,9 @@ module.exports = {
   plugins: [
     new webpack.DefinePlugin(GLOBALS),
     new webpack.optimize.CommonsChunkPlugin('vendors', 'vendors.js'),
+    new webpack.optimize.OccurenceOrderPlugin(true),
     new webpack.optimize.UglifyJsPlugin({
+      sourceMap: false,
       compress: {
         warnings: false
       }