UnknownMethodCallError during tests

[Radomir Dopieralski]

Exception in thread Thread-1:
Traceback (most recent call last):
  File "/usr/lib64/python2.7/threading.py", line 811, in __bootstrap_inner
    self.run()
  File "/home/sheep/tuskar-ui/.venv/lib/python2.7/site-packages/openstack_dashboard/api/ceilometer.py", line 359, in run
    stats_attr=self.stats_attr, additional_query=self.additional_query)
  File "/home/sheep/tuskar-ui/.venv/lib/python2.7/site-packages/openstack_dashboard/api/ceilometer.py", line 577, in update_with_statistics
    query=query, period=period)
  File "/home/sheep/tuskar-ui/.venv/lib/python2.7/site-packages/openstack_dashboard/api/ceilometer.py", line 307, in statistic_list
    statistics = ceilometerclient(request).\
  File "/home/sheep/tuskar-ui/.venv/lib/python2.7/site-packages/mox.py", line 608, in __getattr__
    raise UnknownMethodCallError(name)
UnknownMethodCallError: Method called is not a member of the object: statistics

[Ana Krivokapić (akrivoka)]

This was fixed in https://review.openstack.org/#/c/113472.