Add testing for 2.6 and PyPy3.

Better off to start compatible and remove support if needed.
dev-requirements: Use detox, it's just faster.
CleanCommand: Add "dist" to `user_options`.
Add support for cleaning up after sdist.
Add support for cleaning up after bdist.
Don't remove directories unless told to.
Update for 0.0.1 release.
Merge pull request #1 from dave-shawley/add-dist-support

Remove distribution directories.