Fix polyfill, #210

src/index.js

+import 'babel-polyfill';
 import dva from 'dva';
 import 'moment/locale/zh-cn';
-import './polyfill';
 import './g2';
 import './rollbar';
 // import browserHistory from 'history/createBrowserHistory';

src/polyfill.js

-import 'core-js/es6/map';
-import 'core-js/es6/set';
-import 'babel-polyfill';
-
-global.requestAnimationFrame =
-  global.requestAnimationFrame || function requestAnimationFrame(callback) {
-    setTimeout(callback, 0);
-  };