Fulcrum Query API Driver

I don't already see a way to do this - so wondering if it's something that contributes/developers would consider adding. If there is a way to do this already - please let me know and close the issue.

The ability to connect to a service such as [Fulcrumapp Query API](http://developer.fulcrumapp.com/query-api/intro/) - this is essentialy a postgresql database with postgis extensions.

Thanks,
Ry

Start with the Fulcrumapp Query API documentation linked in the issue and compare its PostgreSQL/PostGIS behavior with Metabase's existing database support. No repository files, tests, or entry points are named. Done would mean a supported connection to the Fulcrum Query API and the ability to query its data.

Written by the indexing model from the issue text.