title: Specify where to install 'tests_require' dependencies of a distribute/setuptools package
body: <p>When I run <code>python setup.py test</code> the dependencies listed in <code>tests_require</code> in setup.py are downloaded to the current directory. When I run <code>python setup.py install</code>, the dependencies listed in <code>requires</code> are instead installed to <code>site-packages</code>.</p>
  
  <p>How can I have those <code>tests_require</code> dependencies instead installed in <code>site-packages</code>?</p>