dont remove and add the js loader

Now that the babel config is resolved externally so that it can be
stubbed out and tested, webpack.config.js does not know how to change
the loader based on the stage.

lib/utils/webpack.config.js

@@ -281,13 +281,6 @@ module.exports = (program, directory, stage, webpackPort = 1500, routes = []) =>
             require('postcss-reporter'),
           ],
         })
-        config.removeLoader('js')
-        config.loader('js', {
-          test: /\.jsx?$/, // Accept either .js or .jsx files.
-          exclude: /(node_modules|bower_components)/,
-          loader: 'babel',
-          query: babelConfig(program, stage),
-        })
         return config
 
       case 'build-css':