Update Heat system tests

- Added Ceilometer install option to enviroments
(test autoscaling now needed Ceilometer)
- Remove import of Heat image, now tests use TestVM image
- Added running of new test 'test_update'

Closes-Bug: #1404233
Change-Id: I31ba48b62dc6114e290d7cce7acfbeeb9aa2e93a
Merge "Update Heat system tests"