Remove Nova dependencies from hacking test

References to Nova in the docstrings(!) of the hacking.py tests caused the
run_pep8.sh script to fail if the Grizzly development version of Nova was
not installed. Update all the references to use Heat packages instead.

Change-Id: I2e84e9a231451705d61fa9acddc65ee95a98e294
Merge "Remove Nova dependencies from hacking test"