Use tox for tests

tox.ini

@@ -0,0 +1,14 @@
+# Tox (http://tox.testrun.org/) is a tool for running tests
+# in multiple virtualenvs. This configuration file will run the
+# test suite on all supported python versions. To use it, "pip install tox"
+# and then run "tox" from this directory.
+
+[tox]
+envlist = py26, py27
+
+[testenv]
+# install_command requires tox>=1.6
+install_command = pip install --process-dependency-links {opts} {packages}
+commands = nosetests
+deps =
+    nose