refactor:refine webpack.prod.conf.js

.babelrc

 {
   "presets": [
     ["env", {
-      "modules": false,
-      "targets": {
-        "browsers": ["> 1%", "last 2 versions", "not ie <= 8"]
-      }
+      "modules": false
     }],
     "stage-2"
   ],

build/webpack.prod.conf.js

@@ -27,11 +27,10 @@ var webpackConfig = merge(baseWebpackConfig, {
   output: {
     path: config.build.assetsRoot,
     filename: utils.assetsPath('js/[name].[chunkhash].js'),
-    chunkFilename: utils.assetsPath('js/[id].[chunkhash].js'),
+    chunkFilename: utils.assetsPath('js/[name].[chunkhash].js'),
     publicPath: config.build.assetsPublicPath
   },
   plugins: [
-    new webpack.optimize.ModuleConcatenationPlugin(),
     // http://vuejs.github.io/vue-loader/en/workflow/production.html
     new webpack.DefinePlugin({
       'process.env': env,
@@ -77,6 +76,8 @@ var webpackConfig = merge(baseWebpackConfig, {
     }),
     // cache Module Identifiers
     new webpack.HashedModuleIdsPlugin(),
+    // enable scope hoisting
+    new webpack.optimize.ModuleConcatenationPlugin(),
     // split vendor js into its own file
     new webpack.optimize.CommonsChunkPlugin({
       name: 'vendor',