Modernize examples
Modernize examples

Fix legacy syntax. Also wrangled into here is an attempt to exert some
backpressure on the async call benchmark to get a real sense of how
quickly async calls are being dispatched.

Even with this improvement, variance is still ~18% which indicates
something screwey is still happening.

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