Update #48 - Added ReceiptOutputStrategy & ReceiptGUIOutput classes.
Update #49 - Modified Receipt class:
1) Changed LineItem from an array to a List:
FROM: LineItem[] lineItems = new LineItem[0];
TO: List<LineItem> lineItems = new ArrayList<LineItem>();

2) Changed addToArray() method code:
FROM: 
//        LineItem[] tempItems = new LineItem[lineItems.length + 1];
//        System.arraycopy(lineItems, 0, tempItems, 0, lineItems.length);
//        tempItems[lineItems.length] = item;
//        lineItems = tempItems;
TO:
        lineItems.add(item);

3) Changed for loop within generateReceipt() method: 
FROM: 
//        for (int i = 0; i < lineItems.length; i++) {
//            System.out.println(lineItems[i].getLineItem());
//        }
TO:
        for (LineItem lineItem: lineItems) {
            System.out.println(lineItem.getLineItem());
        }

4) Changed for loop within calculateDiscount() method:
FROM:
//        for (int i = 0; i < lineItems.length; i++) {
//            dTotal += (lineItems[i].calculateDiscount());
//        }
TO:
        for (LineItem item: lineItems) {
            dTotal += item.calculateDiscount();
        }
Update #50 - Removed the ReceiptGUIOutput & ReceiptOutputStrategy classes from the project.  Will work to add these again at some point in the future.
Update #51 - Removed commented out code in the addToArray() method in the Receipt class.  Also added finalize() to the 10th test in the Startup class.