title: Could not find a version that satisfies the requirement in python
body: <p>I am trying to create virtual env with python2 in mac os from <a href="http://sourabhbajaj.com/mac-setup/Python/virtualenv.html" rel="noreferrer">here</a>.
  While running <code>pip install virtualenv</code> command in terminal I am getting following error.</p>
  
  <pre><code>Could not find a version that satisfies the requirement virtualenv (from versions: )
  No matching distribution found for virtualenv
  </code></pre>