Added spec for Celluloid::Registry#delete method
Added spec for Celluloid::Registry#delete method

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