This patch enables the "versions controller" or "/" resource to display
information relevant to all the versions of the Barbican API (which is
only v1 at the moment). This is done in the same fashion Keystone
displays it, and it has the purpose of enabling more automatic discovery
as described in the blueprint.
Accessing the root resource with the "build" query parameter, such as:
$ curl http://localhost:9311/?build
will display the build information.
On the other hand, this introduces the V1Controller, which is now the
root controller (which requires authentication) for Barbican.
Accessing the "/v1" resource will display the version information in the
way it's required by keystone.
The json-home implementation is left for a subsequent CR.
Partially implements blueprint fix-version-api
Change-Id: Ie7e706adcf1b5d74f64776b888a06638247b4e87
3b20d84312