Fix ElevatorMonitor Update

[ryandash]

• move the updating of the elevator monitor to every time the compareFloors() method is used
• set the elevator to idle every time stopAtFloor() is called (this should fix the bug causing the elevator door status to not change)
• remove removedRequest == null check from attemptToRemoveFloor() method as removedRequest is never null according to the compiler
• clean up compareFloors() method as there is very little difference between idle and active code
• update elevatorMonitor when elevator stops but before opening the door (movement: idle and door: closed)

Before reviewing please CHECK with the expected output in the order below where open and close is the door status and floor1, floor2, etc is the floor#

Elevator1: open floor1 close, floor2 open close floor3 open close, floor4, floor5 open close, floor6 open
Elevator2: open floor1 close, floor2 open close, floor3, floor4 open close, floor5, floor6, floor7 open close, floor6, floor5, floor4 open close, floor3 open close, floor2, floor1 open

[withaspirit]

Seems to be in order with 1 Elevator