gnocchi: deploy services with Keystone v3 endpoints

gnocchi: deploy services with Keystone v3 endpoints

* Move swift_authurl to gnocchi-base hieradata, where other swift auth
  credentials live and switch it to versionless keystone endpoint.
* Force swift_auth_version to 3 for Keystone v3.
* Switch auth_uri to use versionless Keystone endpoint.
* Switch auth_url to use Keystone admin endpoint (instead of internal).
* Remove old parameters from gnocchi::api, not used anymore.

Partial-blueprint: keystone-v3

Change-Id: I2feed8b1219069128faa1a1e8dcd2ddfbae7e40a