closes: GRADE-923
test plan:
1. run migrations
2. all submissions have anonymous IDs:
Submission.joins(assignment: :course).
where(anonymous_id: nil).
merge(Course.active).
exists? # => false
Change-Id: Ic5588841698c3a6d9e18baf6bdf023f7903801eb
Reviewed-on: https://gerrit.instructure.com/144251
Reviewed-by: Shahbaz Javeed <sjaveed@instructure.com>
Tested-by: Jenkins
Reviewed-by: Keith T. Garner <kgarner@instructure.com>
QA-Review: Indira Pai <ipai@instructure.com>
Reviewed-by: Rob Orton <rob@instructure.com>
Product-Review: Keith T. Garner <kgarner@instructure.com>
Derek Bender