I just tried updating a bot I made last week with hubot 2.19.0 to hubot@next (ie 3.0.0), and I was getting this warning:
$ npm install --save hubot@next
npm WARN engine hubot@3.0.0: wanted: {"node":">4","npm":">2"} (current: {"node":"4.8.3","npm":"2.15.11"})
Maybe the node version needs to be >= 4?
cc @gr2m hubotio/evolution#4