Add ability to automate testing with tox.

Install tox via easy_install. Tox automates the creation of multiple
virtual environments, each of which can be used with a different
interpreter or specific custom tests (and is what StackForge uses).

Signed-off-by: Jeff Peeler <jpeeler@redhat.com>

tox.ini

@@ -0,0 +1,34 @@
+[tox]
+envlist = py27,pep8
+
+[testenv]
+setenv = VIRTUAL_ENV={envdir}
+deps = -r{toxinidir}/tools/pip-requires
+       -r{toxinidir}/tools/test-requires
+commands = {toxinidir}/run_tests.sh -N -P
+
+[tox:jenkins]
+sitepackages = True
+downloadcache = ~/cache/pip
+
+[testenv:pep8]
+deps = pep8
+commands = /bin/bash run_tests.sh -N --pep8
+
+[testenv:coverage]
+commands = /bin/bash run_tests.sh -N -P --coverage
+
+[testenv:venv]
+commands = {posargs}
+
+[testenv:jenkins27]
+basepython = python2.7
+deps = file://{toxinidir}/.cache.bundle
+
+[testenv:jenkinscover]
+deps = file://{toxinidir}/.cache.bundle
+commands = /bin/bash run_tests.sh -N --coverage
+
+[testenv:jenkinsvenv]
+deps = file://{toxinidir}/.cache.bundle
+commands = {posargs}