Update users/models.py to make use of geodjango by importing the required modules and changing start and end location fields on Item() to Points
Update Driver.get_nearby_items() to use geodjango spacial queries to return a queryset of items with pickup and delivery locations within a given distance of a location. Add Driver.get_static_map_nearby_items() to return URI for static Google map with markers for nearby items.
Update requirements.txt with psycopg2 since so that PostGIS can be used as the database