title: authentication with urllib3
body: <p>I am trying to connect to a webpage using urllib3. The code is provided below.</p>
  
  <pre><code>import urllib3
  http=urllib3.PoolManager()
  fields={'username':'abc','password':'xyz'}
  r=http.request('GET',url,fields)
  </code></pre>
  
  <p>If we assume that url is some webpage which needs to be authenticated using username and password, am i using the right code to authenticate ?</p>
  
  <p>I have did this using urllib2 very comfortably but i was not able to do the same thing using urllib3. </p>
  
  <p>Many Thanks</p>