IE不支持 Promise 解决办法

引入 <script src = "https://cdn.polyfill.io/v2/polyfill.min.js"></script> 
或 <script type="text/javascript" src ="https://cdn.polyfill.io/v2/polyfill.min.js?features=es6"></script>

参考地址：https://blog.csdn.net/HH921227/article/details/79989430