Refactor returnBook function
    Removed:
	canReturnBook
    Created new test:
	testSucessReturnBook
	testFailedReturnBook
    Test removed:
	canReturnBook
	cannotReturnBook
	returnBook
Changes to commit:
	modified:   controllers/updateBook.py
	modified:   tests/unittest/testUpdateBook.py
Merge Commit
Refactor borrowBook
    In borrowBook()
	used the removedAvailableCopies
    methods:
	remove canBorrowBook
    test:
	modified to pass

Changes to commit:
	modified:   controllers/updateBook.py
	modified:   tests/unittest/testUpdateBook.py