title: POSTing and GETing with grequests
body: <p>I'm using grequests to scape websites faster. However, I also need to login to the website. </p>
  
  <p>Before (just using requests) I could do: </p>
  
  <p>where <code>headers</code> is my <code>User-Agent</code>. </p>
  
  <pre><code>with requests.Session() as s: 
      s.headers.update(headers)
      s.post(loginURL, files = data)
      s.get(scrapeURL)
  </code></pre>
  
  <p>Using <code>grequests</code> I've only been able to pass <code>headers</code> by doing: </p>
  
  <pre><code>rs = (grequests.get(u, headers=header) for u in urls)
  response = grequests.map(rs)
  </code></pre>
  
  <p>Is there anyway to do a <code>POST</code> at the same time so I can login? The login URL is differnt than the URL(s) I'm scrapping. </p>