title: Axios not sending custom header during options request
body: <p>I have a running Vue.js application that request to the server.
  My client-side application is running on e.g. <code>cms.abc.com</code> and the server in ApiGee running on this dns <code>server.abc.com</code></p>
  <p>The request code using axios is</p>
  <pre><code>const headers = {
    'x-api-key': 'xxxxx123123'
  }
  
  return axios({
    method: get,
    url: 'server.abc.com/items',
    headers: headers
  }).then(response =&gt; {
    console.log(respnose.data)
  })
  </code></pre>
  <p>When I check the browser network I'm getting status <code>401 Unauthorized</code> during <code>OPTIONS</code> request.
  The APIgee CORS has been enabled, but when I check the logs from the ApiGee the value for <code>x-api-key</code> is missing.</p>
  <p>I'm also not sure why my client side application is still sending OPTIONS request. I'm expecting that it should skip the CORS since the client and the server are having the same origin. which is <code>abc.com</code></p>