错误：Error: Chunk.entry was removed. Use hasRuntime()
卸载npm uninstall extract-text-webpack-plugin --save-dev
重新下载 npm install extract-text-webpack-plugin@^2.0.0-beta.4
错误：Error: Breaking change: extract now only takes a single argument.
原因是webpack2对loader的配置做了一些调整，修改 ExtractTextPlugin配置即可：
{ test: /\.less$/, use: ExtractTextPlugin.extract({ fallback: ‘style-loader‘, use: [‘css-loader‘, ‘less-loader‘] }) },
