Borrado logico de libros(zzz buuu)
Cambios a los modelos para implementar el carro
Avanzada la agregada de libros al carro
Merge remote-tracking branch 'origin/entregable' into Oman-rails

Conflicts:
	cookbooks/Gemfile.lock
	cookbooks/app/views/books/show.html.erb
	cookbooks/config/database.yml