<!--[if lte IE 8]>
  <script src="https://cdn.jsdelivr.net/core-js/2/shim.min.js"></script>
<![endif]-->

<!--[if lte IE 8]>
  <script src="https://cdn.polyfill.io/v2/polyfill.min.js"></script>
<![endif]-->

Use polyfill.io to shim es5 and fix tests
Use polyfill.io to shim es5 and fix tests
