title: Request header field Content-Type is not allowed by Access-Control-Allow-Headers AngularJS
body: <p>I am working on an API module that makes CORS requests to the service endpoint:<br>
  <a href="https://github.com/gigablox/angular-blitline-api" rel="nofollow noreferrer">https://github.com/gigablox/angular-blitline-api</a></p>
  
  <p>See the demonstration here:<br>
  <a href="http://plnkr.co/FjnJbHQHG5MM7P0VbtV6" rel="nofollow noreferrer">http://plnkr.co/FjnJbHQHG5MM7P0VbtV6</a></p>
  
  <p>You will notice when the API call is made I receive the following error message:<br>
  <code>Request header field Content-Type is not allowed by Access-Control-Allow-Headers</code></p>
  
  <p>I've open sourced a few of these API modules before for --- <em>Imgur</em>, <em>Mandrill</em>, and <em>Blogger</em> --- but this is the first time I've ever seen this problem using <em>Blitline</em>.</p>
  
  <p>Is there an issue in my code or does the service provider not like the way the request is being sent to them because of some AngularJS <code>$http</code> convention?</p>
  
  <p>I was able to find a <a href="https://stackoverflow.com/questions/16661032/http-get-is-not-allowed-by-access-control-allow-origin-but-ajax-is">related topic</a> however the solution provided did not work.<br>
  <code>delete $httpProvider.defaults.headers.common['X-Requested-With'];</code><br>
  Feel free to try it with that plunker --- I should note I am using <strong>1.1.5</strong></p>