Add GeoAlchemy2 and Shapely to requirements
Add map_coordinates and area columns to hearings and show in frontend

The migration in this commit asumes that the db user is superuser. If that's not the case
the instructions CREATE EXTENSION postgis and DROP EXTENSION postgis will fail.
Add tests to hearing map
Add postgis extension to test database
Allow page scrolling when map is on hover and make attribution smaller
Use GeoJson as format to send geo data to angular

It also gets rid of map_coordinates column in the database. Now it gets calculated from the hearing area.
Adapt zoom to area size
Fix imports
fix migrations order
Merge pull request #61 from fastmonkeys/feature/hearing-maps-from-db

Feature/hearing maps from db