Use download authorization in FullZipController

Author: nygrenh

app/controllers/full_zip_controller.rb

@@ -1,7 +1,7 @@
 class FullZipController < ApplicationController
   def index
     submission = Submission.find(params[:submission_id])
-    authorize! :read, submission
+    authorize! :download, submission
     exercise = submission.exercise
     base_name = "#{submission.user.login}-#{exercise.name}-#{submission.id}"
     data = SubmissionPackager.get(exercise).get_full_zip(submission, base_name)