refactoring: adjusted discription of test to fit result

src/test/py/test_primitive_calculations.py

@@ -21,7 +21,7 @@ class primitive_calculations(unittest.TestCase):
     def test_add_1_dot_5_plus_1_dot_5_equals_3(self):
         self.assertEqual(add(1.5, 1.5), 3)
 
-    def test_subtract_5_minus_5_equals_10(self):
+    def test_subtract_5_minus_5_equals_0(self):
         self.assertEqual(subract(5, 5), 0)