title: google is not defined in react app using create-react-app
body: <p>I create a react app using the cli called create-react-app. Look like Facebook did lots of things underneath, such as webpack etc. However, I guess it may also has some limitations. I try to follow <a href="http://www.klaasnotfound.com/2016/11/06/making-google-maps-work-with-react/" rel="noreferrer">this tutorial</a> to load google map api. And when I debug my code, I can see the google map has been successfully referenced.<a href="https://i.stack.imgur.com/gBUPE.png" rel="noreferrer"><img src="https://i.stack.imgur.com/gBUPE.png" alt="enter image description here"></a>.</p>
  
  <p>But then I click play and let application finishes running. I got google is not defined error from webpackHotDevClient.js and my application crashes.</p>
  
  <p><a href="https://i.stack.imgur.com/tzbXv.png" rel="noreferrer"><img src="https://i.stack.imgur.com/tzbXv.png" alt="enter image description here"></a></p>
  
  <p><a href="https://i.stack.imgur.com/2CklM.png" rel="noreferrer"><img src="https://i.stack.imgur.com/2CklM.png" alt="enter image description here"></a></p>
  
  <p>Since webpack compile the files on the fly, I assume it has trouble to load google map via https?</p>
  
  <p>Any thoughts?</p>