Remove additional purge test
Remove additional purge test

We recently added a new integration test for purge to check purge per
project. It doesn't provide much more testing, and we can't actually
have 2 purge tests because they can't run in parallel to each other, so
let's remove it for now.

Change-Id: I9f0b97adae9ea532bc2453441c327e30b849d006
Closes-Bug: #1608910

noironetworks/heat,cwolferh/heat-scratch,noironetworks/heat,openstack/heat,openstack/heat,cwolferh/heat-scratch