Create heat-specific patrole gate

Creates a heat-specific patrole gate, because heat's policy.json
uses different roles than most projects: heat_stack_user, in
particular. Two gates will be added:
  - admin heat non-voting gate
  - heat_stack_user heat non-voting gate

This patch updates the post_test_hook to only execute heat
patrole tests if the second argument passed to the script
is "heat".

Change-Id: I6e9f909e4be5e0be94e910f3a1b0eb22bb74ee38
Depends-On: I05a53ce80453b7488233bf765951837a3d86209f
1 file changed