Remove polyfills

src/common/polyfill.js

-// Source: https://gist.github.com/paulirish/1579671
-(function () {
-  let lastTime = 0;
-  const vendors = ['ms', 'moz', 'webkit', 'o'];
-
-  for (let x = 0; x < vendors.length && !window.requestAnimationFrame; ++x) {
-    window.requestAnimationFrame = window[`${vendors[x]}RequestAnimationFrame`];
-    window.cancelAnimationFrame = window[`${vendors[x]}CancelAnimationFrame`] || window[`${vendors[x]}CancelRequestAnimationFrame`];
-  }
-
-  if (!window.requestAnimationFrame) {
-    window.requestAnimationFrame = function (callback) {
-      const currTime = new Date().getTime();
-      const timeToCall = Math.max(0, 16 - (currTime - lastTime));
-      const id = window.setTimeout(
-        () => { callback(currTime + timeToCall); },
-        timeToCall,
-      );
-      lastTime = currTime + timeToCall;
-      return id;
-    };
-  }
-
-  if (!window.cancelAnimationFrame) {
-    window.cancelAnimationFrame = function (id) {
-      clearTimeout(id);
-    };
-  }
-}());

src/index.js

 import Overlay from './core/overlay';
 import Element from './core/element';
 import Popover from './core/popover';
-import './common/polyfill';
 import {
   CLASS_CLOSE_BTN,
   CLASS_NEXT_STEP_BTN,