pycadf now supports Python3

Adding pycadf back into the requirements file so that we can remove the
magic mocking.

bp python3

Change-Id: Id379ed4ea48bda903307568dde9fdc673a98e4e7

keystone/tests/unit/__init__.py

@@ -26,7 +26,6 @@
     from unittest import mock  # noqa: our import detection is naive?
 
     sys.modules['oslo'].messaging = mock.Mock()
-    sys.modules['pycadf'] = mock.Mock()
     sys.modules['paste'] = mock.Mock()
 
 # NOTE(dstanek): oslo_i18n.enable_lazy() must be called before

requirements-py3.txt

@@ -32,6 +32,5 @@ oauthlib>=0.6
 pysaml2
 dogpile.cache>=0.5.3
 jsonschema>=2.0.0,<3.0.0
-# pycadf tries to pull in eventlet
-# pycadf>=0.6.0
+pycadf>=0.8.0
 posix_ipc