title: How do I force `setup.py test` to install dependencies into my `virtualenv`?
body: <p>In a crusade to make my application <code>pip</code>-installable, I'm fighting big fights with <code>setuptools</code> and <code>distribute</code>. I assume my dependencies are correct, i.e. installing with <code>pip install myapp</code> should probably fill the virtual environment correctly. However, I'd like to streamline development while I'm at it, so my goal is to start with an empty <code>virtualenv</code> and make <code>setup.py test</code> (and later <code>setup.py develop</code>, but that's a whole different fight) fill it with all defined dependencies.</p>
  
  <p>And now to my problem: no matter how hard I try, all I get are dependencies installed as <code>.egg</code>s in my project directory which is sub-optimal at the very least. I tried creating a new <code>setuptools</code> command which would use <code>pip</code> (which seems to work, even though awkwardly) but that can't seriously be the solution (subclassing and overriding that is).</p>
  
  <p>So how do I make <code>setup.py test</code> fill the <code>virtualevn</code> instead of my working directory?</p>