Adds setup.py (python package information)

Added a basic setup.py, so that I can use `pip install git+git://github.com/pstch/django-github-hook.git`

Also allows you to register the package in the python package index

I didn't really know what to put in the package metadata, so I've put your name and email as they were public on your GitHub profile. Feel free to change that if it's annoying to you.