vue-cli 2.x项目，删除打包线上环境的控制台打印

在build/webpack.prod.conf.js里面

添加如下代码

const webpackConfig = merge(baseWebpackConfig, {
    plugins: [
       new webpack.optimize.UglifyJsPlugin({ //自动删除console.log
          compress: {
            warnings: false,
            drop_debugger: true,
            drop_console: true,
            pure_funcs: ['console.log']
          },
          sourceMap: true,
          parallel: true,
        }),    
    ]

})