code: def forwards(apps, schema_editor):
      
      Movie = apps.get_model('spectator_events', 'Movie')
      Work = apps.get_model('spectator_events', 'Work')
      WorkRole = apps.get_model('spectator_events', 'WorkRole')
      WorkSelection = apps.get_model('spectator_events', 'WorkSelection')
  
      for m in Movie.objects.all():
  
          work = Work.objects.create(
              kind='movie',
              title=m.title,
              title_sort=m.title_sort,
              year=m.year,
              imdb_id=m.imdb_id
          )
  
          for role in m.roles.all():
              WorkRole.objects.create(
                  creator=role.creator,
                  work=work,
                  role_name=role.role_name,
                  role_order=role.role_order
              )
  
          for selection in m.events.all():
              WorkSelection.objects.create(
                  event=selection.event,
                  work=work,
                  order=selection.order
              )
  
          m.delete()
docs: Change all Movie objects into Work objects, and their associated
      data into WorkRole and WorkSelection models, then delete the Movie.