set_question_set method in questions controller, and fixed path in index.json.builder
working on put update test
added pry-byebug
added redirect to class groups index when logged in
working on put update test
added redirect to class groups index when logged in
added class group model validation tests
added error spec when class group name is blank
removed space
fixed merge conflicts
fixed merge conflicts
removed blank lines
Validate class group model. Closes #54
Fix broken json endpoint in QuestionsController
created test for limiting class group view
updated #create tests because it was hard-coded to one class group and I made a 2nd one for  testing show
limited ClassGroup#create to verified users
created enrolled? method and added to controller
closes #93
fixed small issue from rebasing