Add raketask to delete old quiz submissions
Find the quiz via the id
Keep track of updated and created at timestamps
Spell submission correctly
Merge branch 'master' into tristan_binary_classifier
fixing CL binary classifier quiz per slide
Merge branch 'tristan_binary_classifier' into tristan-master
fixing duplicate slide for quizz in CL
Merge branch 'tristan_binary_classifier' into tristan-master
dumb db change before merge
db, rolled back timestamp..
Merge branch 'tristan_voter_challenge' into tristan-master