Update; add headers to py files

weather/weather_cli.py

@@ -1,3 +1,13 @@
+# weather_cli.py
+# ------------
+# By MWC Contributors
+#
+# Defines a CLI (command-line interface) for weather. 
+# This is the program that will actually run when you 
+# run `weather` in Terminal. 
+#
+# You don't need to do anything with thie file.
+
 from argparse import ArgumentParser
 from weather.weather import print_weather