Add mock to test requirements.

edx/analytics/tasks/tests/test_course_enroll.py

@@ -66,6 +66,7 @@ class CourseEnrollEventMapTest(unittest.TestCase):
 
     def test_missing_event_type(self):
         event_dict = self._create_event_dict()
+        event_dict['old_event_type'] = event_dict['event_type']
         del event_dict['event_type']
         line = json.dumps(event_dict)
         self.assert_no_output_for(line)

requirements/test.txt

-nose
-nose-ignore-docstring
+nose==1.3.0
+nose-ignore-docstring==0.2
 coverage==3.7
 pep8==1.4.5
 pylint==0.28
 diff-cover >= 0.2.1
+mock==1.0.1