Adding checkpoint for robe0635

Completed checkpoint 3, please see the below repository link and commit log for any further information,

https://github.com/robe0635/se3prac3
https://github.com/robe0635/se3prac3/commits/master/tilt.c

If this is correct this would be my 6th checkpoint checked off so i can pass without any trouble :)
Thanks again, Jayden Roberts