Added new clone_db command for bootstrapping database

`./manage.py clone_db` builds a Django database on your local machine from scratch using the server's API endpoints.
- Don't have to scrape for 6 hours to have a working copy of the data anymore; instead, takes about 6 minutes to get just the CountyInmate data
- Can supply `--api` and `--limit` options to have more control.

Note that for the time being, CourtDate and HousingHistory APIs seem not to work with `limit=0`, which is the default. Recommendation: run `./manage.py clone_db -a 'countyinmate, courtlocation, housinglocation'` instead (or just `-a countyinmate`). You can follow up with a limited call to CourtDate and HousingHistory APIs if you want.