Upgraded to run on Mavericks, with virtualenv and requirements.txt

Thanks for writing this script! This is the minimum viable hack it took to get it running on OSX 10.9 (Mavericks).

I may dig into it a bit more later, as it appears in its current state the icon is not Bartender-friendly, and I'm not sure why -- I don't know anything about OSX menubar apps.

Anyhow, not sure if you're still maintaining this, but here's a PR if you want it!  :beer: