title: Cannot add custom header for $http.get in angularJS
body: <p>So, I am doing this request:</p>
  
  <pre><code>$http({
      method: 'GET',
      url: query,
      headers: { 'api-key': 'test-api-key' }
  });
  </code></pre>
  
  <p>In Chrome Developer Tools Network tab I can see the request being sent:</p>
  
  <blockquote>
  <pre><code>Accept:*/*
  Accept-Encoding:gzip, deflate, sdch
  Accept-Language:en-US,en;q=0.8,sv;q=0.6
  Access-Control-Request-Headers:accept, api-key
  Access-Control-Request-Method:GET
  Cache-Control:no-cache
  Connection:keep-alive
  Host:my-host.myhost.net
  Origin:http://localhost:24153
  Pragma:no-cache
  Referer:http://localhost:24153/
  User-Agent:Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/47.0.2526.80 Safari/537.36
  X-FirePHP-Version:0.0.6
  </code></pre>
  </blockquote>
  
  <p><strong>Q: What possible reasons may there be that the header is not added to the request?</strong> </p>