chore(CONTRIBUTING): remove references to CoffeeScript
chore(CONTRIBUTING): remove references to CoffeeScript

lisb/hubot,github/hubot,hubotio/hubot,github/hubot,scboucher/hubot,nandub/hubot,lisb/hubot,PropertyUX/nubot,lisb/hubot,scboucher/hubot,nandub/hubot,hubotio/hubot,PropertyUX/nubot