In order to allow tests to work as the use of the common
role is implemented in the various roles, we pre-implement
the addition of the role into the a-r-r file.
Change-Id: I69d9d1b8b5ea7c62425e1d38e7f551ebe3cc57c3
Implements: blueprint python-build-install-simplification
Signed-off-by: Jesse Pretorius <jesse.pretorius@rackspace.co.uk>