fixing pylint violations

src/brewing/brew_potions.py

@@ -4,6 +4,7 @@ from brewing import cooking
 from brewing import inspection
 
 def make_example_potion(student_name="ASPP student"):
+    """Make and return an example potion."""
     my_potion = potion_class.Potion(student_name=student_name)
     # Set up your old kettle and light an eternal flame underneath it.
     my_potion.setup(container=containers.OLD_KETTLE)