Add Ruby2.0.0 build in Travis-ci, and allowed to fail
Add Ruby2.0.0 build in Travis-ci, and allowed to fail

ktheory/resque,timo-p/resque,vladimirich/resque,delectable/resque,sideci-sample/sideci-sample-resque,sufery/resque,ryan-drake-stoker/resque,tylerdooling/resque,sideci-sample/sideci-sample-resque,AlexVPopov/resque,igorjancic/resque,rutikasb/resque,bonekost/resque,m0dd3r/resque,redhotpenguin/resque,jonatas/resque,lileeyao/resque,tylerdooling/resque,fmitech/resque,lileeyao/resque,eileencodes/resque,lukeasrodgers/resque,ducthanh/resque,ngpestelos/resque,igorjancic/resque,lukeasrodgers/resque,sufery/resque,l4u/resque,stitchfix/resque,delectable/resque,m0dd3r/resque,vladimirich/resque,partap/resque,stitchfix/resque,jacknguyen/resque,ktheory/resque,l4u/resque,paran0ids0ul/resque,vietnt/resque,paran0ids0ul/resque,kangkot/resque,bhighley/resque,fmitech/resque,hoffmanc/resque,hoffmanc/resque,begriffs/resque,ychaim/resque,begriffs/resque,jacknguyen/resque,timo-p/resque