sf / san francisco needs a cities update

[dancrew32]

https://github.com/codeforamerica/three/blob/master/three/cities.py#L112-L120

produces a 404. I think these two sections need to update endpoint to

https://mobile311.sfgov.org/open311/v2/

[Mr0grog]

It might be useful (if you’re making use of this module longer-term) to sync that file up with https://github.com/codeforamerica/open311status/, either by adding an API to that service or by having a build-time tool that copies https://github.com/codeforamerica/open311status/blob/master/config/cities.yml