extract-text-webpack-plugin插件提取css单独打包

安装方法：
npm install extract-text-webpack-plugin –save-dev
使用：

const ExtractTextPlugin = require('extract-text-webpack-plugin')//引入module.exports = {     plugins: [        new ExtractTextPlugin({            filename: 'css/[name].css' //路径以及命名        })     ],     module: {        rules: [            {                test: /\.vue$/,                loader: 'vue-loader',                options: {                    loaders: {                        less: ExtractTextPlugin.extract({ fallback: 'vue-style-loader', use: 'css-loader!less-loader' }),                        css: ExtractTextPlugin.extract({ fallback: 'vue-style-loader', use: 'css-loader' })                    }                    // other vue-loader options go here                }            },            {                test: /\.css$/,                loader: ExtractTextPlugin.extract({ fallback: 'style-loader', use: 'css-loader' }),                exclude: /node_modules/,            }      ]}