title: Cannot set property 'Swiper' of undefined
body: <p>I just added the Swiper 4.0.2 from the cdnjs.
  But as soon as I refresh the page, this error shows up on my console.</p>
  
  <pre><code>swiper.js:16 Uncaught TypeError: Cannot set property 'Swiper' of undefined
  </code></pre>
  
  <p>This is swiper.js line 16:</p>
  
  <pre><code>13   (function (global, factory) {
  14     typeof exports === 'object' &amp;&amp; typeof module !== 'undefined' ? module.exports = factory() :
  15     typeof define === 'function' &amp;&amp; define.amd ? define(factory) :
  16     (global.Swiper = factory());
  17   }(this, (function () { 'use strict';
  </code></pre>
  
  <p>It seems that <code>global</code> is undefined.
  Can anyone please help?</p>
  
  <p>Thank you.</p>