Remove explicit references to acl files.

jeepyb can infer the location of the acl file given a base acl_dir.

Change-Id: I19f54cf86821456f1d5c9803cb6e34bb83df5c55
Depends-on: Ib17e21851978972205bc3342347a72cf9b078c6c
Reviewed-on: https://review.openstack.org/23373
Reviewed-by: James E. Blair <corvus@inaugust.com>
Approved: James E. Blair <corvus@inaugust.com>
Tested-by: Jenkins