Remove createfromenv test environment dependency

The createfromenv deployment function uses the environment variable
OS_REGION_NAME, but the tests did not correctly mock this variable.
Consequently setting this env var before running tests would cause the
tests to fail. This patch corrects the mock.

Change-Id: I15fe174cd9700ff34791c6980fa52ff975055e02
Closes-Bug: #1308029
Merge "Remove createfromenv test environment dependency"