Add flow control skeleton and expected functions
Flesh out _get_donors() & _add_donor()
Add _add_donation() to add a donor's donation to the master list
Add #! usr/... to make list_lab.py run from cmd line
Add _print_donors() for aesthetics
Add _generate_ty(), _print_ty_menu(), and _print_main_menu() to make print formatting easier
Add _get_donations() to return a donor's donations
Add _print_donations() to format donations
Redefine _print_donations() to accept list of donations instead of donor name
Change _print_donations() to return values instead of print