Repo setup and basic vagrant box

This sets up a basic vagrant box that has some dependencies we need or are likely to need, along with git flow for the repo (reminder: you need to do this manually on your local machine after cloning).

There are still some things that need to be done, like setting up a Django app, running syncdb, and CI integration if we're doing that. I didn't want to go too far with this and get in the way of the people who will actually implement those things.