Add tox config.

Add a config file for tox to enable running salt tests in a set of
virtualenvs for different versions of python. Add stanzas to allow
for running tests against 2.6, 2.7 and 3.2.

First step - pip install tox. Then, to run tests in a virtualenv
against all three, simply type:

tox

If you want to  run against just one, try:

tox -epy26

And if you want to see more, do:

tox -v -epy26

.gitignore

@@ -17,3 +17,5 @@ lib/
 pip/
 share/
 
+# tox - ignore any tox-created virtualenv dirs
+.tox

setup.py

@@ -14,7 +14,7 @@ from distutils.sysconfig import get_python_lib, PREFIX
 if os.environ.get('VIRTUAL_ENV'):
     from setuptools import setup
 
-execfile('salt/version.py')
+exec(compile(open("salt/version.py").read(), "salt/version.py", 'exec'))
 
 class TestCommand(Command):
     description = 'Run tests'

tox.ini

@@ -0,0 +1,12 @@
+[tox]
+envlist = py26,py27,py32
+
+[testenv]
+setenv = VIRTUAL_ENV={envdir}
+deps = -r{toxinidir}/requirements.txt
+       unittest2
+commands = bash -c 'cd tests && python runtests.py'
+
+[testenv:py32]
+basepython = python3.2
+deps = -r{toxinidir}/requirements.txt