Add GTFS Converter

[omar-kabbani]

To address https://github.com/spur-sim/spur/issues/27 Added GTFS_converter.py which takes in GTFS files (routes.txt, stop_times.txt, stops.txt, and trips.txt) and generates corresponding input files for spur (components.json, routes.json, tours.json)

Limitations:

• Yards are not generated
• Code assumes double track operations for trips A -> B and B -> A
• Mean boarding and alighting times are hardcoded as constants

I used the GO Transit GTFS data to test: https://www.gotransit.com/en/partner-with-us/software-developers

Please let me know what you think!

[wklumpen]

Hey Omar,

Been through this a bunch now diagnosing some issues, and I think we'll need to take another stab. There's a few "gotchas" in the model that we'll need to think through, such as:

• The last component of a route on a tour has to be the same component of the next route on that tour
• The way tours are being generated doesn't quite line up parameter wise (getting a mismatch on the number of parameters)

There might be a hybrid way we can clean up some of the extra mess that comes with GTFS so that it works back into the Spur system. I'll give it some thought.

For now I suggest we mark this as hold.