title: virtualenv doesn't work on git bash MINGW32
body: <p>I'm a git newbie.
  I'm working on Windows and I use Git Bash MINGW32.
  I was working in my directory on master Branch
  in "env" environmental (created by myself with virtualenv).
  For an error I close my shell and now I cannot reactivate env environemntal.
  I try with </p>
  
  <pre><code>env\Scripts\activate
  </code></pre>
  
  <p>but i cannot see env in the prompt.
  I try to create another virtual environmental using</p>
  
  <pre><code>VIRTUALENV env1
  </code></pre>
  
  <p>and then</p>
  
  <pre><code>env1\Scripts\activate
  </code></pre>
  
  <p>But i don't see env1 in the prompt.</p>
  
  <p>If I create a test virtual environmental using msdos prompt it works.</p>
  
  <p>Any tips?</p>