load submission needs grading notification

test plan:
  - As a teacher, create a quiz with an essay question and publish the
    quiz. Set your notification preferences for grading to
    "Immediately".
  - As a student, take the quiz.
  - As the teacher, you should get a notification that the submission
    needs reviewing.

fixes CNVS-6524

Change-Id: I185a10175fcc9528100a1157049ecca5ffcccff5
Reviewed-on: https://gerrit.instructure.com/22642
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Derek DeVries <ddevries@instructure.com>
QA-Review: Myller de Araujo <myller@instructure.com>
Product-Review: Stanley Stuart <stanley@instructure.com>

Author: Stanley Stuart

db/migrate/20130724222101_load_submission_needs_grading_notification.rb

@@ -0,0 +1,16 @@
+class LoadSubmissionNeedsGradingNotification < ActiveRecord::Migration
+
+  tag :postdeploy
+
+  def self.up
+    Canvas::MessageHelper.create_notification({
+      name: 'Submission Needs Grading',
+      delay_for: 0,
+      category: 'Grading'
+    })
+  end
+
+  def self.down
+    Notification.find_by_name('Submission Needs Grading').destroy
+  end
+end