added hayl0017 to prac 3,4,5,6,7,8

Pracs 3, 4, and 7 in test.c
https://github.com/jhaylock/se3prac3

Prac 5
https://github.com/jhaylock/se3prac3/blob/master/prac5.md

Prac 6 
https://github.com/jhaylock/se3prac3/blob/master/prac6.md

Prac 8
https://github.com/jhaylock/se3prac3/blob/master/prac8.md