test error

$ py.test -vv -s test_network_api_service.py 
161017-18:52:47.748 dcostests.dcos _get_hostname() INFO: Test if host `master.mesos` can be resolved.
161017-18:52:47.750 dcostests.dcos _make_ca_crt_file() INFO: Attempt to get CA bundle via CA HTTP API
/opt/mesosphere/lib/python3.5/site-packages/requests/packages/urllib3/connectionpool.py:821: InsecureRequestWarning: Unverified HTTPS request is being made. Adding certificate verification is strongly advised. See: https://urllib3.readthedocs.org/en/latest/security.html
  InsecureRequestWarning)
161017-18:52:48.193 root _wait_for_leader_election() INFO: leader.mesos dns entry is UP!
161017-18:52:48.223 root _wait_for_Marathon_up() INFO: Marathon is probably up
161017-18:52:48.242 root _wait_for_slaves_to_join() INFO: Sufficient (2 >= ['10.0.7.227', '10.0.0.66']) number of slaves have joined the cluster
161017-18:52:48.255 root _wait_for_DCOS_history_up() INFO: DC/OS History is probably up
161017-18:52:48.255 root _wait_for_srouter_slaves_endpoints() INFO: Fetching agents from Mesos
161017-18:52:48.273 root _wait_for_srouter_slaves_endpoints() INFO: Fetching agent state from /slave/8d205b9b-9009-43fe-9df6-2597f8e7d378-S0/slave%281%29/state.json
161017-18:52:48.297 root _wait_for_srouter_slaves_endpoints() INFO: Fetching agent state from /slave/8d205b9b-9009-43fe-9df6-2597f8e7d378-S1/slave%281%29/state.json
==================================================================================================================================================== test session starts =====================================================================================================================================================
platform linux -- Python 3.5.2, pytest-2.9.2, py-1.4.31, pluggy-0.3.1 -- /opt/mesosphere/packages/python--d46cb3fd035721d01ce7811510352bc1d3bc771d/bin/python3
cachedir: .cache
rootdir: /opt/mesosphere/packages/dcos-integration-test-ee--3d93a3f87bc6a199ee14201f26143d3e43eb0604, inifile: pytest.ini
plugins: teamcity-messages-1.19, html-1.9.0
collected 2 items 

test_network_api_service.py::test_network_api_vips ERROR
test_network_api_service.py::test_network_api_named_vips ERROR

=========================================================================================================================================================== ERRORS ===========================================================================================================================================================
__________________________________________________________________________________________________________________________________________ ERROR at setup of test_network_api_vips ___________________________________________________________________________________________________________________________________________

    @pytest.fixture(scope="session", autouse=True)
    def use_custom_ca():
        for m in ['get', 'post', 'put', 'delete', 'patch', 'head', 'options']:
>           orig = getattr(test_util.cluster_api.ClusterApi, m)
E           AttributeError: module 'test_util' has no attribute 'cluster_api'

conftest.py:27: AttributeError
_______________________________________________________________________________________________________________________________________ ERROR at setup of test_network_api_named_vips ________________________________________________________________________________________________________________________________________

    @pytest.fixture(scope="session", autouse=True)
    def use_custom_ca():
        for m in ['get', 'post', 'put', 'delete', 'patch', 'head', 'options']:
>           orig = getattr(test_util.cluster_api.ClusterApi, m)
E           AttributeError: module 'test_util' has no attribute 'cluster_api'

conftest.py:27: AttributeError