Session3 -- mailroom check-in

Nearly done with mailroom.py.  Still need to add final if __name__ ==' __main__' block but the other components are finished so it seemed like a good time to check in.  
Agreed, it wasn't the best solution but I wasn't sure how else I could ensure the names and donations remained firmly linked.  In the end this scheme required creating a new record with the added donation and replacing the entire existing record (name + donation tuple) for each loop.