message: prod source map
diff: @@ -23,6 +23,8 @@ export default (webpackConfig) => {
  'react-dom' : 'ReactDOM',
  }
  + webpackConfig.devtool = 'cheap-module-source-map'
  +
  webpackConfig.module.rules = webpackConfig.module.rules.map((loader) => {
  if (loader.test.test('*.css') || loader.test.test('*.scss')) {
  loader.use = ExtractTextPlugin.extract({
  