code: function (webpackConfig, paths) {
  
      var defaultWebpackConfig = {
          output: {
              filename: paths.output.name,
          },
          module: {
              loaders: [
                  {
                      test: /\.vue$/,
                      loader: 'vue'
                  },
              ]
          },
      };
  
      if (fs.existsSync('webpack.config.js')) {
          var customWebpackConfig = require('./../../webpack.config.js');
          defaultWebpackConfig = _.extend(defaultWebpackConfig, customWebpackConfig);
      }
  
      webpackConfig = _.extend(defaultWebpackConfig, webpackConfig);
  
      if (!_.contains(webpackConfig.module.loaders, {test: /\.vue$/, loader: 'vue'})) {
          webpackConfig.module.loaders.push({
              test: /\.vue$/,
              loader: 'vue'
          });
      }
  
      if (config.sourcemaps) {
          webpackConfig = _.defaults(
              webpackConfig,
              {devtool: '#source-map'}
          );
      }
  
      if (config.production) {
          var currPlugins = _.isArray(webpackConfig.plugins) ? webpackConfig.plugins : [];
          webpackConfig.plugins = currPlugins.concat([new UglifyJsPlugin({sourceMap: false})]);
      }
  
      return webpackConfig;
  }
docs: Handle webpack config such as sourcemaps and
  minification or user's cunstom webpack config.
  
  @param {object} options
  @return {object}