Book.java
- Added String type ‘title’
- Added new constructor to include ’title’

Main.java
- Added Main.java (mostly still empty)

BookFactory.java
- Added newBook(String) for the new ‘title’ implementation
- Added getBook(String) to look through ArrayList for Book with the
given ‘title’
- Error handling for both getBook still needs more work

BookFactory is now implemented to handle all the books.

Added some simple functions including rent() and calculating
overdueFine()