Clear up virtualenv arguments in fab functions
Fix the virtualenv paths after creating next copy

The files in 'bin/' inside the virtualenv hardwire the full path of the
python executable into the #! line (and occasionally into other lines).
So after doing a copy, we should fix the paths to ensure we're using the
correct python (and other paths).
Add commented out text for pytest in manage.py

Need to sort this out better, but it's a start.
Add *.sql.gz to gitignore in cookiecutter bit
Refactor dump/restore db to use with(open...)

to better ensure the files are closed
Add test for restore db
Add test for db.dump_db()