payload class is a string not a ruby constant
payload class is a string not a ruby constant

Fixes #500

m0dd3r/resque,dylanahsmith/resque,ducthanh/resque,coupa/resque,fmitech/resque,lileeyao/resque,hoffmanc/resque,stvp/resque,stitchfix/resque,bhighley/resque,begriffs/resque,AlexVPopov/resque,amiel/resque,Shopify/resque,coupa/resque,ktheory/resque,resque/resque,resque/resque,tylerdooling/resque,begriffs/resque,lukeasrodgers/resque,partap/resque,CloudVLab/resque,BIAINC/resque,vladimirich/resque,ychaim/resque,timo-p/resque,amiel/resque,tylerdooling/resque,redhotpenguin/resque,coupa/resque,rutikasb/resque,stitchfix/resque,jacknguyen/resque,ejlangev/resque,CloudVLab/resque,fmitech/resque,paran0ids0ul/resque,paran0ids0ul/resque,dylanahsmith/resque,sideci-sample/sideci-sample-resque,github/resque,sufery/resque,CloudVLab/resque,vietnt/resque,delectable/resque,resque/resque,jacknguyen/resque,kangkot/resque,jonatas/resque,BIAINC/resque,ktheory/resque,github/resque,igorjancic/resque,vladimirich/resque,redsquirrel/resque,l4u/resque,hoffmanc/resque,xiangzhuyuan/resque,eileencodes/resque,redsquirrel/resque,bonekost/resque,xiangzhuyuan/resque,m0dd3r/resque,ryan-drake-stoker/resque,xiangzhuyuan/resque,timo-p/resque,igorjancic/resque,stvp/resque,ejlangev/resque,stvp/resque,ngpestelos/resque,lileeyao/resque,Shopify/resque,sufery/resque,delectable/resque,lukeasrodgers/resque,sideci-sample/sideci-sample-resque,Shopify/resque,github/resque,l4u/resque