Improve the api versioning

- Don't use the project version for the API, but
  the actual API version (just v1 defined now).
- Change the return type to a list of versions (we can't be
  that optimistic).

blueprint api
Change-Id: Icb8c0c91798cf4eb1e10b39040e123119e859d10
Merge "Improve the api versioning"