vue 打包去掉console debugger

修改build/webpack.prod.conf.js文件中plugins

 new UglifyJsPlugin({
      uglifyOptions: {
        compress: {
          warnings: false,
          drop_debugger: true,
          drop_console: true,
        }
      },
      sourceMap: config.build.productionSourceMap,
      parallel: true
    })