Multi role RBAC validation

This patchset replaces ``CONF.patrole.rbac_test_role`` with
``CONF.patrole.rbac_test_roles``, where instead of single role
we can specify list of roles to be assigned to test user.

Change-Id: Ia68bcbdbb523dfe7c4abd6107fb4c426a566ae9d
diff --git a/patrole_tempest_plugin/config.py b/patrole_tempest_plugin/config.py
index dc0ed25..90d5fba 100644
--- a/patrole_tempest_plugin/config.py
+++ b/patrole_tempest_plugin/config.py
@@ -22,8 +22,16 @@
 PatroleGroup = [
     cfg.StrOpt('rbac_test_role',
                default='admin',
+               deprecated_for_removal=True,
+               deprecated_reason="""This option is deprecated and being
+replaced with ``rbac_test_roles``.
+""",
                help="""The current RBAC role against which to run
 Patrole tests."""),
+    cfg.ListOpt('rbac_test_roles',
+                help="""List of the RBAC roles against which to run
+Patrole tests.""",
+                default=['admin']),
     cfg.ListOpt('custom_policy_files',
                 default=['/etc/%s/policy.json'],
                 help="""List of the paths to search for policy files. Each