Introduce a deployment script via Fabric

Simple deployment script that checks out the latest
revision of the code base, does a requirements check (and
install if need be), and finally boots a gunicorn worker
that an nginx configuration on the server looks for.

To use, you must install the packages in `requirements-dev.txt`, and then run the Fabric command:

    fab deploy

That's it! It'll go in and do everything described and finally close the connection to the server.