fix build error

Author: filipesilva

packages/@angular/cli/models/webpack-test-config.ts

@@ -1,4 +1,3 @@
-import * as webpack from 'webpack';
 const webpackMerge = require('webpack-merge');
 
 import { BuildOptions } from './build-options';
@@ -28,11 +27,6 @@ export class WebpackTestConfig extends NgCliWebpackConfig {
     ];
 
     this.config = webpackMerge(webpackConfigs);
-    // delete this.config.entry;
-
-    // Remove any instance of CommonsChunkPlugin, not needed with karma-webpack.
-    // this.config.plugins = this.config.plugins.filter((plugin: any) =>
-    //   !(plugin instanceof webpack.optimize.CommonsChunkPlugin));
 
     return this.config;
   }