title: Create react app proxy doesn't redirect request
body: <p>I have created react app with <a href="https://facebook.github.io/create-react-app/docs/proxying-api-requests-in-development" rel="nofollow noreferrer">create-react-app</a></p>
  
  <p>So the backed server listens on port <code>5000</code>. The react server listens on port <code>3000</code>.</p>
  
  <p>I added this line <code>"proxy": "http://localhost:5000"</code> to package JSON. 
  Now when I do a request like this:</p>
  
  <pre><code>GET /api/hello HTTP/1.1
  Host: 192.168.0.102
  Content-Type: application/json
  </code></pre>
  
  <p>to the react app. I get this message:</p>
  
  <pre><code>+IPD,420:HTTP/1.1 404 Not Found
  X-Powered-By: Express
  Content-Security-Policy: default-src 'self'
  X-Content-Type-Options: nosniff
  Content-Type: text/html; charset=utf-8
  Content-Length: 148
  Vary: Accept-Encoding
  Date: Sat, 03 Nov 2018 11:18:11 GMT
  Connection: keep-alive
  
  &lt;!DOCTYPE html&gt;
  &lt;html lang="en"&gt;
  &lt;head&gt;
  &lt;meta charset="utf-8"&gt;
  &lt;title&gt;Error&lt;/title&gt;
  &lt;/head&gt;
  &lt;body&gt;
  &lt;pre&gt;Cannot GET /api/hello&lt;/pre&gt;
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>This is a link to the proj files : <a href="https://github.com/RadoslavMarinov/stack-show" rel="nofollow noreferrer">https://github.com/RadoslavMarinov/stack-show</a></p>