Support for os_domain_name and openstack v3

[ioggstream]

Hi @all,

I'm testing the templates with openshift enterprise 3.5. and it seems that /etc/origin/cloudprovider/openstack.conf complains about keystone v2 endpoints

I resolved this step adding the os_domain_name parameter in the playbooks/templates. If this works I'll submit a pull request.

If you have hints about how should I implement this, please let me know.

[ioggstream]

merged https://github.com/redhat-openstack/openshift-on-openstack/pull/336