Added Some Classes

-The ‘ProcessControlBlock’ class will model the processes that come in
from SOS. More fields and methods will be added to this.

-The ‘ProcessTable’ class holds a list of ‘ProcessControlBlock’
objects. More fields and methods will be added, if we need them.

-The ‘MainTest’ class is just a dummy class for us to test out and
debug the other classes before we test against the SOS class. The
‘MainTest’ class won’t be in our final project.