Use tox to easily run tests in venv

tox https://pypi.python.org/pypi/tox is a thin wrapper around virtualenv
which let you craft a fresh python environement to execute command in.

It creates the env with virtualenv, install dependencies, run python
setup.py install in it and then execute whatever command you want it to
do and report status.

To do so I simply:

- listed tests dependencies in test-requirements.txt (which are just
  nose and mock)
- provide a tox.ini file which describe how to install the dependencies
  and execute nosetests
- added the module 'coverage' to the list of test dependencies

To run tests simply:

 pip install tox && tox

That will execute the test command 'nosetests' using python2.6 and then
python 2.7.

The additional env 'cover' can be run using: tox -ecover.

.gitignore

@@ -9,3 +9,6 @@ cover/
 /doc/_build
 nbproject
 *.sublime-workspace
+
+/*egg-info
+/.tox

README.md

@@ -13,8 +13,9 @@ The object database implementation is optimized for handling large quantities of
     -  Tested with nose 1.3.0
 * Mock by Michael Foord used for tests
     - Tested with 1.0.1
+* Coverage - used for tests coverage
 
-The list of dependencies are listed in /requirements.txt. The installer takes care of installing them for you though.
+The list of dependencies are listed in /requirements.txt and /test-requirements.txt. The installer takes care of installing them for you though.
 
 ### INSTALL
 
@@ -32,6 +33,16 @@ A distribution package can be obtained for manual installation at:
 
     http://pypi.python.org/pypi/GitPython
 
+### RUNNING TESTS
+
+The easiest way to run test is by using [tox](https://pypi.python.org/pypi/tox) a wrapper around virtualenv. It will take care of setting up environnements with the proper dependencies installed and execute test commands. To install it simply:
+
+    pip install tox
+
+Then run:
+
+    tox
+
 ### DEVELOPMENT STATUS
 
 [![Build Status](https://travis-ci.org/gitpython-developers/GitPython.svg?branch=0.3)](https://travis-ci.org/gitpython-developers/GitPython)

test-requirements.txt

@@ -0,0 +1,4 @@
+# Remember to update README.md
+coverage
+nose
+mock

tox.ini

@@ -0,0 +1,13 @@
+[tox]
+envlist = py26,py27
+
+[testenv]
+commands = nosetests
+deps = -r{toxinidir}/requirements.txt
+       -r{toxinidir}/test-requirements.txt
+
+[testenv:cover]
+commands = nosetests --with-coverage
+
+[testenv:venv]
+commands = {posargs}