fix test failure with ironic client

The watcher.tests.common.test_clients.TestClients.test_clients_ironic unit
test's been failure since python-ironicclient 2.5.2 release. In that release,
we fixed a bug with the interface argument was ignored.

https://docs.openstack.org/releasenotes/python-ironicclient/rocky.html#relnotes-2-5-2-stable-rocky

Therefore, we need to adjust the ironic test case in watcher to account for
the interface argument.

Change-Id: Iedb27efc9f296054fcbd485b27736a789cee3496

watcher/tests/common/test_clients.py

@@ -410,6 +410,7 @@ class TestClients(base.TestCase):
         mock_call.assert_called_once_with(
             CONF.ironic_client.api_version,
             endpoint_override=ironic_url,
+            interface='publicURL',
             max_retries=None,
             os_ironic_api_version=None,
             retry_interval=None,