Added geolocation and US bubble visualization

Now when looking at the United States, a map with geolocated bubbles
will be seen. Bubbles are relative based on percent growth during
selected time period. Map visualization is not yet implemented for rest
of world. Updated data import process, tags are now proper case. Fixed
a bug with location import. Geolocation is now done on cities returned
from Meetup API, which is saved to Neo4j as lat/lng.