modigied gem file
added users controller. Added link to enrollment page on home page. created new student view.
Added functioning 'Enrollment' (sign up) feature
added 'Roster page' which lists all students enrolled on Classtronomy
added functioning edit and delete buttons

Each student's show page has an edit and delete button.
Made form partial. Added validation to form.

Form partial now rendered in new and edit views.
Added Sign In/Sign Out

Students must now sign in to access content
adding styling and courses controller