More detailed error message on unexpected message type
More detailed error message on unexpected message type

This error throws from time to time in our specs. We suspect it's a race condition, but it'd be nice to have some more detail in the message when it fires.
davydovanton/celluloid,marshall-lee/celluloid,sideci-sample/sideci-sample-celluloid,celluloid/celluloid,olleolleolle/celluloid,kenichi/celluloid,jasonm23/celluloid,seuros/celluloid,dilumn/celluloid,TiagoCardoso1983/celluloid