This commit slots in a new migration before remove-non-normalized-badge-uploads
to add an ON DELETE CASCADE clause to the badge_image table foreign key
constraint. The former failed in production due to foreign key constraints with
the badge_image table; running both of these together should allow the
fix to succeed.
Remove hardcoded reference to 'openbadges' in migration
Merge pull request #852 from stenington/828-broken-upload

Add ON DELETE CASCADE to badge_image table