Configure Keystone API enable

Add KEYSTONE_ENABLED_APIS to select which Keystone APIs to
enable, default to both 2 and 3.

Note, v3 only doesn't currently work ...

Change-Id: Ia4b0cf12810a29889c932ae9d0df28f2f104ac97
Set service domain

Change-Id: I0431acfa96367b14048682efdd96ba6aa12f2e5e
Merge branch 'tls-update' into dt-test
Merge branch 'conf-tempest' into dt-test
Merge branch 'test-service-functions' into dt-test
Merge branch 'exercise-refresh' into dt-test