please include tests in the pypi tarball

[sandrotosi]

Hey there! i noticed setup.py requires mock for tests, but in the tarball released on pypi the file tests.py is missing - could you add it the next time you cut a release? tahnsk!

[rennat]

I've started a local branch to improve the source distribution (and automate more of this so it is less of a hassle)
Expect this in 0.8.1 soon.