Code review comment for lp:~corey.bryant/charms/trusty/nova-cloud-controller/git-ods

Looks OK - but see unit test failure on merged branch:

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ERROR: test_config_changed_single_consoleauth (unit_tests.test_nova_cc_hooks.NovaCCHooksTests)
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Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/mock.py", line 1210, in patched
    return func(*args, **keywargs)
  File "/home/jamespage/src/charms/git/nova-cloud-controller/unit_tests/test_nova_cc_hooks.py", line 800, in test_config_changed_single_consoleauth
    hooks.config_changed()
  File "hooks/nova_cc_utils.py", line 1005, in wrapped_f
    f(*args)
  File "hooks/charmhelpers/core/host.py", line 312, in wrapped_f
    f(*args, **kwargs)
  File "hooks/nova_cc_hooks.py", line 180, in config_changed
    if config_value_changed('openstack-origin-git'):
  File "hooks/charmhelpers/contrib/openstack/utils.py", line 346, in config_value_changed
    with hook_data():
  File "/usr/lib/python2.7/contextlib.py", line 17, in __enter__
    return self.gen.next()
  File "hooks/charmhelpers/core/unitdata.py", line 425, in __call__
    self._record_charm_version(hookenv.charm_dir())
  File "hooks/charmhelpers/core/unitdata.py", line 435, in _record_charm_version
    os.path.join(charm_dir, 'revision')).read().strip()
  File "/usr/lib/python2.7/posixpath.py", line 70, in join
    elif path == '' or path.endswith('/'):
AttributeError: 'NoneType' object has no attribute 'endswith'