Fixes test_images_member_rbac missing os credentials for image v2.

Currently Patrole test in image.v2.test_images_member_rbac fails
because of an AttributeError [0], related to the attribute 'os'
missing, meaning that the credentials array lacks the 'primary'
user. This patch adds the 'primary' user to the credentials
array for this test.

[0] http://logs.openstack.org/94/444994/4/check/gate-tempest-dsvm-patrole-admin-ubuntu-xenial-nv/370bc2d/console.html

Change-Id: I62050cc8595acb87b49ecb9e9c6ff80503591bc3
Partial-Bug: #1670553
diff --git a/patrole_tempest_plugin/tests/api/image/v1/test_images_member_rbac.py b/patrole_tempest_plugin/tests/api/image/v1/test_images_member_rbac.py
index 8ded2ec..c062769 100644
--- a/patrole_tempest_plugin/tests/api/image/v1/test_images_member_rbac.py
+++ b/patrole_tempest_plugin/tests/api/image/v1/test_images_member_rbac.py
@@ -30,12 +30,11 @@
     def setup_clients(cls):
         super(ImagesMemberRbacTest, cls).setup_clients()
         cls.image_member_client = cls.os.image_member_client
-        cls.alt_image_member_client = cls.os_alt.image_member_client
 
     @classmethod
     def resource_setup(cls):
         super(ImagesMemberRbacTest, cls).resource_setup()
-        cls.alt_tenant_id = cls.alt_image_member_client.tenant_id
+        cls.alt_tenant_id = cls.os_alt.image_member_client.tenant_id
 
     def tearDown(self):
         self.rbac_utils.switch_role(self, switchToRbacRole=False)
diff --git a/patrole_tempest_plugin/tests/api/image/v2/test_images_member_rbac.py b/patrole_tempest_plugin/tests/api/image/v2/test_images_member_rbac.py
index 81bad5f..f11dbd2 100644
--- a/patrole_tempest_plugin/tests/api/image/v2/test_images_member_rbac.py
+++ b/patrole_tempest_plugin/tests/api/image/v2/test_images_member_rbac.py
@@ -28,21 +28,19 @@
 
 class ImagesMemberRbacTest(base.BaseV2ImageRbacTest):
 
-    credentials = ['admin', 'alt']
+    credentials = ['admin', 'primary', 'alt']
 
     @classmethod
     def resource_setup(cls):
         super(ImagesMemberRbacTest, cls).resource_setup()
         cls.tenant_id = cls.image_member_client.tenant_id
-        cls.alt_tenant_id = cls.alt_image_member_client.tenant_id
+        cls.alt_tenant_id = cls.os_alt.image_member_client_v2.tenant_id
 
     @classmethod
     def setup_clients(cls):
         super(ImagesMemberRbacTest, cls).setup_clients()
         cls.image_client = cls.os.image_client_v2
-        cls.alt_image_client = cls.os_alt.image_client_v2
         cls.image_member_client = cls.os.image_member_client_v2
-        cls.alt_image_member_client = cls.os_alt.image_member_client_v2
 
     def tearDown(self):
         self.rbac_utils.switch_role(self, switchToRbacRole=False)