Make sure auth_url exists and is not versionless

When getting the Ironic API service URL from the Keystone catalog make
sure that the Keystone API endpoint is present and that it contains the
right version of the API.

Closes-Bug: #1290482
Change-Id: I80fc74a1aea02074baba4839df83e0e694bc8ea6
Merge "Make sure auth_url exists and is not versionless"