Enables no auth for public endpoints

Any endpoint that does not depend on tenant/user should be
accessible without any auth.
Remove confusing/unnecessary 'v1/public' endpoint. we already have
public endpoints that does not have 'v1/public' prefix and we don't
have to force URI to use this prefix to make it public.
User should also be able to list solum supported language packs without
any auth (this will be addressed in a separate commit).

Closes-Bug: #1357539, #1348759
Change-Id: I62bfe7afaf2815455c7d868a3af82b0ffba81709
Merge "Enables no auth for public endpoints"