Update /tracking

Parse more /tracking fields (#55)

* Rename camel case

* Fix twitter error

* Add vehicle id

* Add more data

* Alphabetize

* Rename occupancy status

Add `/vehicles` and update travis config

This release corresponds to the ithaca-transit-backend release of v1.1.2, which sets up /tracking to ping the new /vehicles endpoint.

Includes protobuf parsing of live tracking

This release begins using the protobuf API to parse live tracking. At this point in time, it matches with transit-node:v1.1.1. The reason why it's so far ahead in versions is because I make a new "release" (but don't publish on GitHub) for each iteration of GTFS data -- which is why I don't publish the release as a tag because there is no code change, only static data change.

Continue static fetching and add new gtfs info endpoint

• we still put in tcat-ny-us data manually
• has the new gtfs feed info endpoint