Geocoding + Distance + Duration without Google Maps

[kevinmichaelchen]

This PR brings in OpenStreetMap (OSM) for geocoding and Open Source Routing Machine (OSRM) for distance/duration calculation.

• Dependency injection using fx
• Function that calculates duration between two points
• App should work in degraded state (when Google Maps API_KEY is missing). (See codingsince1985/geo-golang for reverse geocoding needs).

Notes:

• Currently the OSRM library only allows us to request for duration between two points. I've created a PR that will allow us to ask for distance between points as well (see Support annotations for TableRequest gojuno/go.osrm#24)