Do not leak self in SupervisionGroup#initialize
Do not leak self in SupervisionGroup#initialize

kenichi/celluloid,olleolleolle/celluloid,TiagoCardoso1983/celluloid,jasonm23/celluloid,mehta/celluloid,marshall-lee/celluloid,celluloid/celluloid,davydovanton/celluloid,sideci-sample/sideci-sample-celluloid,jstoja/celluloid,dilumn/celluloid,seuros/celluloid