Clean up test environment and remove unused imports.

First round of adding more complete unit test coverage.

Change-Id: Ic1979c499ca6fcb784892a95954a3527539c4e53

tests/utils.py

@@ -2,7 +2,6 @@
 
 import time
 
-import mox
 import testtools
 
 
@@ -10,12 +9,9 @@ class TestCase(testtools.TestCase):
 
     def setUp(self):
         super(TestCase, self).setUp()
-        self.mox = mox.Mox()
         self._original_time = time.time
         time.time = lambda: 1234
 
     def tearDown(self):
         time.time = self._original_time
-        self.mox.UnsetStubs()
-        self.mox.VerifyAll()
         super(TestCase, self).tearDown()