Use testtools as test base class.

On the path to testr migration, we need to replace the unittest base classes
with testtools.
Replace tearDown with addCleanup, addCleanup is more resilient than tearDown.
The fixtures library has excellent support for managing and cleaning
tempfiles. Use it.
Replace skip_ with testtools.skipTest

Part of blueprint grizzly-testtools.

Change-Id: I45e11bbb1ff9b31f3278d3b016737dcb7850cd98

tests/unit/test_lockutils.py

@@ -21,14 +21,13 @@ import select
 import shutil
 import tempfile
 import time
-import unittest
+import testtools
 
 import eventlet
 from eventlet import greenpool
 from eventlet import greenthread
 
 from openstack.common import lockutils
-from openstack.common import testutils
 from tests import utils as test_utils
 
 

tests/unit/test_processutils.py

@@ -15,14 +15,14 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import unittest
+import testtools
 
 import mock
 
 from openstack.common import processutils
 
 
-class UtilsTest(unittest.TestCase):
+class UtilsTest(testtools.TestCase):
     # NOTE(jkoelker) Moar tests from nova need to be ported. But they
     #                need to be mock'd out. Currently they requre actually
     #                running code.
@@ -32,7 +32,7 @@ class UtilsTest(unittest.TestCase):
                           hozer=True)
 
 
-class ProcessExecutionErrorTest(unittest.TestCase):
+class ProcessExecutionErrorTest(testtools.TestCase):
 
     def test_defaults(self):
         err = processutils.ProcessExecutionError()