[fixed] a very long standing issue (it basically existed from the very beginning) by ignoring ".babelrc" files and enabling the ES2015 module syntax transpilation; tree shaking will be available again when both webpack 2.3 and webpack-hot-loader 3.0 come out

Author: thealjey

src/webpack.js

@@ -50,6 +50,7 @@ export const isProduction = 'production' === process.env.NODE_ENV;
  * babelFEOptions.presets.push('my-custom-preset');
  */
 export const babelBEOptions = {
+  babelrc: false,
   presets: ['es2016', 'es2017', 'stage-2', 'react'],
   plugins: [
     ['transform-es2015-modules-commonjs', {loose: true}]
@@ -71,8 +72,13 @@ export const babelBEOptions = {
  */
 export const babelFEOptions = {
   cacheDirectory: true,
+  babelrc: false,
   presets: [
-    ['es2015', {loose: true, modules: false}],
+    ['es2015', {
+      // temporarily disabled until `webpack` 2.3 and `webpack-hot-loader` 3.0 are available
+      // modules: false,
+      loose: true
+    }],
     'es2016', 'es2017', 'stage-2', 'react'
   ],
   plugins: ['transform-runtime']