Add ride sharing exanples for Booking API endpoints

[brylie]

We agreed to start with a ride sharing use case for the mock APIs. Now, we need to mock some ride sharing data for the Booking API: Booking endpoints.

[drtimcooper]

Edoardo and I and the Dutch group are working hard on this. See some work-in-progress in the 2nd half of this document: https://docs.google.com/document/d/1KytXF3ZoTmvBHXuc7N7T3zyhDL_069uLzICZzd7e_Ms/edit?usp=sharing

[brylie]

@drtimcooper would you mind being assigned to this issue, since you are currently working on it?

[drtimcooper]

I'm not really working on it "currently" - instead I'm waiting for the Dutch guys to upload their JSON definitions. But if you want to use me as a bridge between that group and MaaS Alliance, then sure.