Use Travis to push new releases to PyPI

[dhermes]

See
http://docs.travis-ci.com/user/deployment/pypi/

They have thought of everything!

Now we just need to cut a release :)

[dhermes]

@silvolu @jgeewax Do we have a key or password to use to push releases?

[silvolu]

I haz ze power. I'll take a look in the afternoon.

[dhermes]

Great!