add ruby-version with default on 2.1
add ruby-version with default on 2.1

jasonm23/pry,sideci-sample/sideci-sample-pry,tdg5/pry,icebreaker/pry,ooohiroyukiooo/pry,tdg5/pry,josue804/debunker,pvdb/pry,pvdb/pry,printercu/pry,gfvcastro/pry,shockone/pry,scalixte-mdsol/pry,jasonm23/pry,caporta/pry,shockone/pry,ngpestelos/pry,85x14/pry,sferik/pry,jasonm23/pry,raeno/pry,josue804/debunker,scalixte-mdsol/pry,tdg5/pry,raeno/pry,nju520/pry,nju520/pry,raeno/pry,bronzdoc/pry,85x14/pry,jasnow/pry,sferik/pry,scalixte-mdsol/pry,geoffreylitt/pry,caporta/pry,jasnow/pry,printercu/pry,ngpestelos/pry,jasnow/pry,nju520/pry,geoffreylitt/pry,gfvcastro/pry,icebreaker/pry,bronzdoc/pry,ooohiroyukiooo/pry,shockone/pry,ooohiroyukiooo/pry,85x14/pry,caporta/pry