clean up test instructions for developers; fixes #75

Author: dhellmann

docs/en/developers.rst

@@ -67,6 +67,8 @@ Running Tests
 The test suite for virtualenvwrapper uses `shunit2
 <http://shunit2.googlecode.com/>`_ and `tox
 <http://codespeak.net/tox>`_.  To run the tests under bash, sh, and
-zsh, use ``make test`` or just ``tox``.  In order to add new tests,
-you will need to modify or create an appropriate script in the
+zsh for Python 2.4-2.7, use ``tox`` from the top level directory of
+the hg repository.  
+
+Add new tests by modifying or creating an appropriate script in the
 ``tests`` directory.