Use openstack cli instead of heat-keystone-setup-domain

This change updates the juno ansible code to deploy heat's keystone
domain and domain user using the same method used in icehouse code.
Using heat-keystone-setup-domain is slightly cleaner however this tool
is not available in icehouse's heat.

Closes #195
Merge pull request #249 from mattt416/sync_icehouse_heat_changes_with_juno

Use openstack cli instead of heat-keystone-setup-domain