Unittest failed because pyroute2 was updated.

Unittest failed because pyroute2 was updated, so some import will be failed. See example bellow:

kuryr.tests.unit.binding.drivers.test_veth.TestVethDriver.test_port_bind
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Captured traceback:
~~~~~~~~~~~~~~~~~~~
    Traceback (most recent call last):
      File "/home/kiennt/Workspace/kuryr/.tox/py27/local/lib/python2.7/site-packages/mock/mock.py", line 1297, in patched
        arg = patching.__enter__()
      File "/home/kiennt/Workspace/kuryr/.tox/py27/local/lib/python2.7/site-packages/mock/mock.py", line 1353, in __enter__
        self.target = self.getter()
      File "/home/kiennt/Workspace/kuryr/.tox/py27/local/lib/python2.7/site-packages/mock/mock.py", line 1523, in <lambda>
        getter = lambda: _importer(target)
      File "/home/kiennt/Workspace/kuryr/.tox/py27/local/lib/python2.7/site-packages/mock/mock.py", line 1210, in _importer
        thing = _dot_lookup(thing, comp, import_path)
      File "/home/kiennt/Workspace/kuryr/.tox/py27/local/lib/python2.7/site-packages/mock/mock.py", line 1199, in _dot_lookup
        __import__(import_path)
    ImportError: No module named interface

And pyroute's author pushed a commit about ifinfmsg: support interface type plugins [1]:

unittest2.loader._FailedTest.kuryr.tests.unit.binding.drivers.test_ipvlan
-------------------------------------------------------------------------

Captured traceback:
~~~~~~~~~~~~~~~~~~~
    Traceback (most recent call last):
    ImportError: Failed to import test module: kuryr.tests.unit.binding.drivers.test_ipvlan
    Traceback (most recent call last):
      File "/home/kiennt/Workspace/kuryr/.tox/py27/local/lib/python2.7/site-packages/unittest2/loader.py", line 456, in _find_test_path
        module = self._get_module_from_name(name)
      File "/home/kiennt/Workspace/kuryr/.tox/py27/local/lib/python2.7/site-packages/unittest2/loader.py", line 395, in _get_module_from_name
        __import__(name)
      File "kuryr/tests/unit/binding/drivers/test_ipvlan.py", line 17, in <module>
        from kuryr.lib.binding.drivers import ipvlan
      File "kuryr/lib/binding/drivers/ipvlan.py", line 20, in <module>
        IPVLAN_MODE_L2 = ifinfmsg.ifinfo.ipvlan_data.modes['IPVLAN_MODE_L2']
    AttributeError: type object 'ifinfo' has no attribute 'ipvlan_data'

[1] https://github.com/svinota/pyroute2/commit/34557c54266d5bda752b30a4ec08531a50994c94