ch13_r09.py main needs revision

[cpepper]

This is the main() that worked for me.

def main():
    options = get_options(sys.argv[1:])
    if options.command is None:
        print("")
    command = options.command()  # Replaces: command = options.command(options)
    command.execute(options)  # Replaces: command.execute()