Skeleton of EventData.
CybercoachSport determines which attributes of EventData are used from
case to case.
Google Maps shows in Event#new
Migration + updated param methods for events.
Added event#show and #edit.

I have deactivated draggable mode for now, because it doesn’t work
smoothly :(
Cleaning up maps implementation.
Added location to seeded Events (fails otherwise).
Solved merge conflict
Polishing maps integration.
Merge branch 'feature/google_maps' into dev
Filtering event_data now + Added some seeds.
Merge branch 'dev' into feature/event_data

Conflicts:
	app/views/events/show.html.erb
Merge branch 'feature/event_data' into dev
Merge branch 'dev' into feature/followers