Utilise ['openstack']['region'] from cookbook-openstack-common

- Set ['openstack']['orchestration']['region'] to equal ['openstack']['region']
- Add tests for endpoint creation, to confirm region is set.

Change-Id: Ie882f6da89f8e6a4324f7f19d3c9582671610629
Addresses: blueprint uniform-region
Merge "Utilise ['openstack']['region'] from cookbook-openstack-common"