title: Cloudflare cache causes "Access-Control-Allow-Origin" header to not be sent
body: <p>A node JS express app hosted on heroku and configured with cloudflare is displaying a strange behaviour : it works for a couple requests and then fails with "No 'Access-Control-Allow-Origin' header is present on the requested resource."</p>
  
  <p>Purging everything in the cloudflare cache allows the app to work again... until the urls are stored in the cache.</p>
  
  <p>I would like to either allow cached queries to send the headers, or disable caching</p>