Changes

A working local test environment with docker, postgres;
Script to load CSV files to database (see scripts/ populate_db/);
Models following GTFS' standarts (see mobilidade_rio/mobilidade_rio/pontos/models.py);
URLs for pontos now have <site>/gtfs/<entity> prefix;

Example: http://localhost:8010/gtfs/routes instead of http://localhost:8010/routes
Endpoint for stop_times with filtering for stop_id, showing all trips passing by all of them at least once
(see mobilidade_rio/mobilidade_rio/pontos/views.py).

Testing endpoint `stop_times`:

Testing 2 stops 2 stops, trip appears for all stops. URL: http://localhost:8010/gtfs/stop_times/?stop_id=5149BO0001U1,5149BO0002U1 Expected result: 6 Results if doesn't work: 8

Test one stop - for comparison 1 stop, no trip repeated. URL: http://localhost:8010/gtfs/stop_times/?stop_id=5149BO0001U1 Expected result: 6