title: Make all images file point to CDN using Webpack
body: <p>In Ruby on Rails you can just adjust a single line of code to make all the assets use an external assets server. Inside <code>config/environments/production.rb</code> you just uncomment a line: </p>
  
  <pre><code>config.action_controller.asset_host = 'XXXXXXXX.cloudfront.net'
  </code></pre>
  
  <p>So I would like to do the same on a react app. I have used <a href="https://github.com/MikaAK/s3-plugin-webpack" rel="noreferrer">s3-plugin-webpack</a> to upload all the assets but I have having problem changing the url to point to the new images that have just been uploaded. </p>
  
  <p>I work on a isomorphic React app so it render both on server and client side. So I don't looking to make the application run from the CDN.</p>