fix(webpack): uglify by default for production builds

closes #739

lib/resources/content/webpack.config.template.js

@@ -4,7 +4,7 @@ const CopyWebpackPlugin = require('copy-webpack-plugin');
 const ExtractTextPlugin = require('extract-text-webpack-plugin');
 const project = require('./aurelia_project/aurelia.json');
 const { AureliaPlugin, ModuleDependenciesPlugin } = require('aurelia-webpack-plugin');
-const { optimize: { CommonsChunkPlugin }, ProvidePlugin } = require('webpack');
+const { optimize: { CommonsChunkPlugin, UglifyJsPlugin }, ProvidePlugin } = require('webpack');
 // @if transpiler.id='typescript'
 const { TsConfigPathsPlugin, CheckerPlugin } = require('awesome-typescript-loader');
 // @endif
@@ -188,6 +188,9 @@ module.exports = ({production, server, extractCss, coverage} = {}) => ({
     })),
     ...when(production, new CopyWebpackPlugin([
       { from: 'static/favicon.ico', to: 'favicon.ico' }
-    ]))
+    ])),
+    ...when(production, new UglifyJsPlugin({
+      sourceMap: true
+    }))
   ]
 });