Transmodel API - things to fix

[t2gran]

Here is a list of things we should fix in the future version of the Transmodel API

Bike Rental

• Bike rental station coordinates should NOT be optional
• Available number of bikes can be unknown (null)

Places

• Quay.stopPlace can NOT be null. Enforce none null for all child to parent relations.

General

• Consider wrapping arrays in response to be extendable
• Return general Shape, not specific types like Polygon

[t2gran]

I have created a new issue in the opentripplanner repo (not entur repo) that replaces this issue:

https://github.com/opentripplanner/OpenTripPlanner/issues/3217

We maintain the Transmodel API (Sandbox feature) in the main OTP repo, not in the Entur repo.