Added a spec file for this blueprint.
Changed the kolla-ansible script to accept more than one
globals.yml file. That will still be the main one but operators
will be able to create more, under the /etc/kolla/globals.d
directory.
Also added some paragraphs in the quickstart documentation
about this.
Finally, Adding a release note

Change-Id: I34eb91d0e2ed80694594b8fc6801cf8ad77da754
Implements: blueprint multiple-globals-files