Added 3 unit test to test quizzes controller.

test/quizzes_test.py

@@ -1,20 +1,20 @@
 import unittest
 
 from app.controllers.quizzes_controller import QuizzesController
+from app.controllers.activities_controller import ActivitiesController
 
 class QuizzesTest(unittest.TestCase):
 
     def setUp(self):
         # Run tests on non-production data
-        self.ctrl = QuizzesController('quizzes_test.py')
+        self.activites = ActivitiesController()
 
     def test_expose_failure_01(self):
-        """
-        Implement this function and two more that
-        execute the code and make it fail.
-        """
-        self.assertTrue(True, 'Example assertion.')
-
+        # None is not a value that is handled within _save_data() method, which tries to loop over None 
+        self.activites.activities = None
+        self.activites._save_data()
+        # This assert is not expected to be reached
+        self.assertEqual(self.activites.activities, None)
 
 if __name__ == '__main__':
     unittest.main()