Update; add headers to py files

test_friend_functions.py

@@ -1,6 +1,14 @@
+# test_friend_functions.py
+# ------------
+# By MWC Contributors
+# 
+# Defines tests for `friend_functions`. 
+# Run this program with `python test_friend_functions.py`.
+# You don't need to edit thie file.
+
 from unittest import TestCase, main
 from people import friends, family
-from friend_functions_solutions import (
+from friend_functions import (
     count_people, 
     get_email, 
     count_favorite_colors,