title: nodeenv hangs when setting up a new environment
body: <p>I tried using <code>nodeenv</code> in the following way:</p>
  
  <pre><code>$ virtualenv --python=python2.7 venv
  $ source venv/bin/activate
  (venv) $ pip2.7 install nodeenv
  (venv) $ nodeenv --node=0.12.2 nenv
  </code></pre>
  
  <p>But it hangs on:</p>
  
  <pre><code> * Install node (0.12.2)..
  </code></pre>
  
  <p>I am not sure how to investigate this issue. Thoughts? Do I need to install Node before all that (currently, <code>$ node \ -sh: node: command not found</code>)? I was under the impression that the correct version of Node would be installed by <code>nodeenv</code>.</p>