Added config files to snapstack_test.

This helps us not break when transitioning to using the new version of
snapstack, with the config files for each snap in the individual
steps, rather than in a config step.

Change-Id: If845bff36ed7f1256a8150ec806a13d6fb08a05e

tests/snapstack_test.py

@@ -19,6 +19,7 @@ class SnapstackTest(unittest.TestCase):
             snap='keystone',
             script_loc='./tests/',
             scripts=['keystone.sh'],
+            files=['etc/snap-keystone/keystone/keystone.conf.d/database.conf'],
             snap_store=False)))
 
         # Execute the snapstack tests