move gem require-in's to -essentials
move gem require-in's to -essentials

marshall-lee/celluloid,kenichi/celluloid,seuros/celluloid,celluloid/celluloid,davydovanton/celluloid,TiagoCardoso1983/celluloid,jasonm23/celluloid,olleolleolle/celluloid,dilumn/celluloid