Add "member" role to tempest tests

The "member" role is needed by the scenario tests to create secrets when
Secure RBAC is enabled i.e. enable_scope=True

Change-Id: I16ed904eeb27ab7110a7e4e56ef7ea89c8c3c2ab
diff --git a/.zuul.yaml b/.zuul.yaml
index 91d86bb..90566c3 100644
--- a/.zuul.yaml
+++ b/.zuul.yaml
@@ -68,6 +68,8 @@
               enforce_scope: True
         test-config:
           $TEMPEST_CONFIG:
+            auth:
+              tempest_roles: member
             barbican_rbac_scope_verification:
               enforce_scope: True