add test and method for - class Proj, if two or more tasks have same priority number the older task gets priority
add test/methods for - Task, defaults the task as having a completion date of nil
add test and methods for ProjectList, methods initialize with empty projects array and createproject method
add test and methods for - ProjectList class method add_task_to_proj
add test and method for - PL class, can show remaining tasks for a project given PID
add test and method for - Task, can check to see if it includes a task given the task's id
complete tm part 1
remove uneeded files
update tests for ensuring unique id for Task and Project - more robust now