Include (Sub-)version info via an endpoint

[ChrisMalewski]

A version hint (v1) is included in the url.

We should include the version (and subversion) info also in a service response e.g. root endpoint.

This corresponds directly with this issue issue, since helgoland detects the version implicit and not explicit.

[ridoo]

As we agreed on the Web API have to stay backwards compatible. So we will omit the v1 part of the URL from 2.x versions. Having v1 in the URL might create wrong assumptions and leads to confusion about API incompatibilities.

To put it short:

Older clients shall always be able to consume any version of the Series API.

Anyway, what you are suggesting we already discussed recently. We came up with adding a version string in the HTTP response header -- I mean no version negotiation, just a custom info header, which will
help the client to find out. A client have to be smart enough to handle if a particular feature is supported or not.

Is it something you find helpful as well?