fix compatibility: We're not going to support 2.0 and below

src/js/components/root.js

@@ -98,4 +98,4 @@ export default class Root extends Component {
       }
     }
   }
-}
+};

src/js/main.js

@@ -1,4 +1,3 @@
-require('babel/polyfill');
 import React from 'react';
 import Root from 'components/root';
 import store from 'store';