updated unit tests

tests/test_other_functions.py → tests/test_demos.py

@@ -8,5 +8,5 @@ class TestCaseDemoFunction(unittest.TestCase):
     def test_demo_function(self):
         # flip test image
         self.assertTrue(
-            a_demo_function(1) is None
+            a_demo_function(None) == 1
         )