Add RealTime/RealTimeProblem models + migration
Add UI for Real-Time Upload

TODO: Add geotrellis endpoint for importing the Real-Time data
Add merge datasources migration for merge conflict
Add city_name to RealTime
Add gtfs_realtime app with realtime import celery task
Display RealTimeProblems in settings UI
Add basic tests for RealTime
Merge pull request #182 from WorldBank-Transport/feature/real-time-upload

Feature/real time upload