Adding prac3checkpoint for load0016

I have completed checkpoint 3. You can view all the tilt.c commits and repository in the below links:

se3prac3 repo:
https://github.com/load0016/se3prac3

This is a link to the commits:
https://github.com/load0016/se3prac3/commits/master/tilt.c

This will be my 6th checkpoint so I can be assured a pass in the topic.

Thanks,
Scott Loader