Remove old migrations

website/documents/management/commands/migratedocuments.py

website/education/management/commands/migrateeducation.py

website/events/management/commands/migrateevents.py

website/mailinglists/management/commands/migratelists.py

website/members/management/commands/migratemembers.py

...ite/merchandise/management/commands/migratemerchandise.py

...ite/newsletters/management/commands/migratenewsletters.py

website/partners/management/commands/migratepartners.py

website/pizzas/management/commands/migratepizzas.py

website/thabloid/management/commands/migratethabloids.py

website/utils/management/commands/legacylogin.py