Completed the Address Book class.
Completed Hash Address Book project. This address book is a HashMap that
holds HashContacts with integer keys. The program is capable of
adding/removing contacts, getting name of address book, searching
address book, checking for valid contacts, displaying a list of all the
contacts, loading the contacts into the address book, saving the address
book, getting an ArrayList of all the contacts. JUnit tests have been
completed as well.