Adds test description, some formatting

Python/norms.py

@@ -7,9 +7,8 @@ def l2_norm(real_values, numerical_values):
         raise ValueError("Real and numerical value lists must be same length")
 
     combined_values = zip(real_values, numerical_values)
-    return math.sqrt(
-        1 / num_values
-        * sum(
-            (real_value - numerical_value) ** 2
-            for real_value, numerical_value in combined_values
-        ))
+    sum_of_squared_distances = sum((real_value - numerical_value) ** 2
+                                   for real_value, numerical_value
+                                   in combined_values)
+
+    return math.sqrt(1 / num_values * sum_of_squared_distances)

Python/test_geometry.py

@@ -30,6 +30,9 @@ class TestGeometry(unittest.TestCase):
         self.assertEqual(sut.x3, 3)
 
     def test_when_setting_line_points__line_should_have_points(self):
+        """
+        WHEN setting line points THEN line should have points
+        """
         sut = GbLine3D()
 
         point1 = GbPoint3D()