Add "member" role to non-admin test credentials

Some services are enabling "new defaults" RBAC by default. This will require all non-admin users to have either the "member" or "reader" role. This patch updates the Octavia tempest plugin to include the "member" role in test credentials when the tempest plugin is configured for "RBAC_test_type" other than owner-or-admin.

Change-Id: I8aadb98d438943b18a8d72ff54e216930cfd3ccc
diff --git a/octavia_tempest_plugin/tests/test_base.py b/octavia_tempest_plugin/tests/test_base.py
index f0477f4..70d51ba 100644
--- a/octavia_tempest_plugin/tests/test_base.py
+++ b/octavia_tempest_plugin/tests/test_base.py
@@ -71,8 +71,10 @@
             ['lb_observer', CONF.load_balancer.observer_role, 'reader'],
             ['lb_global_observer', CONF.load_balancer.global_observer_role,
              'reader'],
-            ['lb_member', CONF.load_balancer.member_role],
-            ['lb_member2', CONF.load_balancer.member_role]]
+            # Note: Some projects are now requiring the 'member' role by
+            # default (nova for example) so make sure our creds have this role
+            ['lb_member', CONF.load_balancer.member_role, 'member'],
+            ['lb_member2', CONF.load_balancer.member_role, 'member']]
 
     # If scope enforcement is enabled, add in the system scope credentials.
     # The project scope is already handled by the above credentials.