[debian] unit tests with Python 3.5

[Thomas Goirand]

Building 2.6.0 of oslo.concurrency, the below unit test failures were reported. Note that it is important, as Debian is currently switching to Python 3.5 instead of 3.4.

======================================================================
FAIL: unittest2.loader._FailedTest.oslo_concurrency.tests.unit.test_lockutils_eventlet
unittest2.loader._FailedTest.oslo_concurrency.tests.unit.test_lockutils_eventlet
----------------------------------------------------------------------
_StringException: Traceback (most recent call last):
ImportError: Failed to import test module: oslo_concurrency.tests.unit.test_lockutils_eventlet
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/unittest2/loader.py", line 456, in _find_test_path
    module = self._get_module_from_name(name)
  File "/usr/lib/python3/dist-packages/unittest2/loader.py", line 395, in _get_module_from_name
    __import__(name)
  File "/home/zigo/sources/openstack/liberty/python-oslo.concurrency/build-area/python-oslo.concurrency-2.6.0/oslo_concurrency/tests/unit/test_lockutils_eventlet.py", line 20, in <module>
    from eventlet import greenpool
  File "/usr/lib/python3/dist-packages/eventlet/greenpool.py", line 3, in <module>
    from eventlet import event
  File "/usr/lib/python3/dist-packages/eventlet/event.py", line 3, in <module>
    from eventlet import hubs
  File "/usr/lib/python3/dist-packages/eventlet/hubs/__init__.py", line 3, in <module>
    from eventlet import patcher
  File "/usr/lib/python3/dist-packages/eventlet/patcher.py", line 4, in <module>
    from eventlet.support import six
  File "/usr/lib/python3/dist-packages/eventlet/support/__init__.py", line 4, in <module>
    from eventlet.support import greenlets, six
  File "/usr/lib/python3/dist-packages/eventlet/support/greenlets.py", line 3, in <module>
    import greenlet
ImportError: No module named 'greenlet'

======================================================================
FAIL: unittest2.loader._FailedTest.oslo_concurrency.tests.unit.test_processutils
unittest2.loader._FailedTest.oslo_concurrency.tests.unit.test_processutils
----------------------------------------------------------------------
_StringException: Traceback (most recent call last):
ImportError: Failed to import test module: oslo_concurrency.tests.unit.test_processutils
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/unittest2/loader.py", line 456, in _find_test_path
    module = self._get_module_from_name(name)
  File "/usr/lib/python3/dist-packages/unittest2/loader.py", line 395, in _get_module_from_name
    __import__(name)
  File "/home/zigo/sources/openstack/liberty/python-oslo.concurrency/build-area/python-oslo.concurrency-2.6.0/oslo_concurrency/tests/unit/test_processutils.py", line 32, in <module>
    from oslo_concurrency import processutils
  File "/home/zigo/sources/openstack/liberty/python-oslo.concurrency/build-area/python-oslo.concurrency-2.6.0/oslo_concurrency/processutils.py", line 42, in <module>
    if eventlet and eventlet.patcher.is_monkey_patched(time):
AttributeError: module 'eventlet' has no attribute 'patcher'

----------------------------------------------------------------------
Ran 27 tests in 4.203s

FAILED (failures=2)

[Ben Nemec (bnemec)]

py35 gate is currently passing, so this must have been fixed at some point.