This is the first commit, has a title and author, nil id, and book status is available.
This is the second commit it makes books available for checkout
This is the third commit, it checks the status of the book and returns a true or false statement.
This is the forth commit, it has a check in feature
This is the 5th commit, it checks to see if the user has a name.
This commit lets a person check out a book by id.