created notes model and associated specs
added notes controller and view
referenced assignment instance in the notes controller - added markup to index
added link to create new note in the notes index. edited model and controller accordingly
added edit and update methods to notes controller and associated code to views
modified notes controller to include find_assignment method, created form partial for notes
added delete button to notes index view, added destroy method to notes controller
created delete buttons for notes and destroy method in notes controller