Migration: update attendance for historical events
Migration: update attendance for historical events

wking/swc-amy,wking/swc-amy,wking/swc-amy,wking/swc-amy,vahtras/amy,swcarpentry/amy,vahtras/amy,vahtras/amy,swcarpentry/amy,pbanaszkiewicz/amy,pbanaszkiewicz/amy,swcarpentry/amy,pbanaszkiewicz/amy