create add books to library
Implemented the list_book method that displays the set of books from the library
added the method to print out the list of books.
added some code in for class to work from
my code so far, going to merge
Merge branch 'master' of https://github.com/makersquare/Library

Conflicts:
	library.rb
Added the method... I'm not doing so well here.
 I am a ninja and have completed all the initial challenges.  I have passed at a base level.  I need to work on the add ons and fix up the documentation.
added tom's documentation for methods
added attr_accessor and deleted getter and setter methods for borrower name and for book title and author
changed author and title to attr reader instead of accessor for books class
added optional parameters for books