old_contents: from gratipay.wireup import db, env
  from gratipay.models.team import migrate_all_tips
  
  db = db(env())
  
  if __name__ == '__main__':
      migrate_all_tips(db)
  
new_contents: from gratipay.wireup import db, env
  from gratipay.models.team.mixins.tip_migration import migrate_all_tips
  
  db = db(env())
  
  if __name__ == '__main__':
      migrate_all_tips(db)
  
subject: Fix imports in tip migration script