Osmgeocoder

Changelog:

- Add type hints to all interfaces
- Add `_dict` variants for geocoding functions to get _raw_ data instead of formatted strings
- Bugfix: Reading of custom opencage data file for address formatting was broken
- Returned addresses now contain county and state if available

- Fix missing import for structured forward geocoding
- Fix Copy and Paste error in forward geocoding SQL

If you're coming from `2.0.0`, re-run the finalize step to update the SQL functions:

bash
$ pipenv run bin/finalize_geocoder.py --db postgresql://geocoder:passwordlocalhost/osmgeocoder

**Warning:** DB Format changed, you'll have to re-import data

- Fixed forward geocoding speed
- Fixed import scripts to be more resilient
- Made Openaddresses.io completely optional
- Restored compatability with older 3.x python versions
- Restored compatability with older PostgreSQL DB versions (9.5+ if you do no use openaddresses.io)
- Switched to `pipenv`