Bug 441

Note: Note: The given problem is for Version 2.

Steps to reproduce:
1. Add an item that has a Delivery date smaller than the Arrival date.

A test case that given below demonstrates this problem. An item that has a Delivery date smaller than the Arrival date should not enter the warehouse. However, this exception was not handled by our program. Need to implement an Exception Handler.

@Test
	void testMoveToSlot_07() {
		Warehouse wh =  Warehouse.getInstance();
		ArrayList<Slot> slots = new ArrayList<>();
		slots.add(new Slot(1));
		slots.add(new Slot(2));
		slots.add(new Slot(3));
		slots.add(new Slot(4));
		slots.add(new Slot(5));
		
		wh.setSlots(slots);
		
		Item item1 = new Item(1,new Day("13-Oct-2020"),new Day("20-Oct-2020"));
		Item item2 = new Item(2,new Day("13-Oct-2020"),new Day("20-Oct-2020"));
		Item item3 = new Item(3,new Day("13-Oct-2020"),new Day("20-Oct-2020"));
		
		Item newItem = new Item(4,new Day("13-Oct-2020"),new Day("1-Oct-2020"));
		
		boolean result = wh.testResult();
		String msg = "Checking when the departure date is smaller than the system date and arrival date";
		assertEquals(false, result, msg);
	}