Started project to add multi-version testing.
Have verified basic installability across Python versions 2.6, 2.7,
3.2, 3.3, 3.4 and the PyPy version of 2.7.8. Initiated automatic
cross-version testing with pytest and tox.
Tests are very basic at present, but have manually confirmed proper
operation under 2.7, 3.4, and PyPy.