Homework submission for week 1 (assignments/session01/)

Hi, 

I completed required tasks and two optional tasks.

Required tasks via 83906ef

Optional task 1 via 70f284a
To test this option, "python service_lists.py -p 10 20" or "python service_lists.py -h" for help.

Optional task 2 via 3edc2b4
I used test.sh launches multiple parallel tests. I saw failueres for echo_server.py. But, I have not seen failures for echo_select_server.py on my laptop.

Please let me know your comments.

Thanks,

Gary