Split out Neutron ports client

Splitting out a ports client for Neutron.

Partially implements blueprint consistent-service-method-names

Change-Id: I1248cc6132f4a2e40ad13f6177c7ecda834db57d
diff --git a/tempest/tests/common/test_dynamic_creds.py b/tempest/tests/common/test_dynamic_creds.py
index 59a5523..73e180e 100644
--- a/tempest/tests/common/test_dynamic_creds.py
+++ b/tempest/tests/common/test_dynamic_creds.py
@@ -376,7 +376,7 @@
             'tempest.services.network.json.network_client.NetworkClient.'
             'remove_router_interface_with_subnet_id')
         return_values = ({'status': 200}, {'ports': []})
-        port_list_mock = mock.patch.object(creds.network_admin_client,
+        port_list_mock = mock.patch.object(creds.ports_admin_client,
                                            'list_ports',
                                            return_value=return_values)