title: How to set the content-type of request header when using Fetch APi
body: <p>I am using npm 'isomorphic-fetch' to send requests. The problem I am experiencing is I am unable to set the content-type of the request header.</p>
  
  <p>I set a content type of application/json , however the request header are being set to text/plain.</p>
  
  <pre><code>import 'isomorphic-fetch';
  
    sendRequest(url, method, body) {
      const options = {
        method: method,
        headers:{'content-type': 'application/json'},
        mode: 'no-cors'
      };
  
      options.body = JSON.stringify(body);
  
      return fetch(url, options);
    }
  </code></pre>
  
  <p>When I examine the request in my browser the content type is o :</p>
  
  <pre><code>content-type:text/plain;charset=UTF-8
  </code></pre>
  
  <p>Can anyone explain why I am unable to set this property?</p>