Allow  lang to be optional, implements #65
Allow  lang to be optional, implements #65

linclark/jsconf-last-call,luisrudge/microservices-com-service-fabric,FormidableLabs/spectacle,lowsky/spectacle,hartmamt/builder-talk,waywaaard/spectacle,waywaaard/spectacle,lowsky/spectacle,survivejs/react-for-awesome-people,tikotzky/spectacle,rektide/webpush-away-deck,FormidableLabs/spectacle,oliviertassinari/SplitMeBord,survivejs/react-for-awesome-people,oliviertassinari/SplitMeBord,luisrudge/microservices-com-service-fabric,tikotzky/spectacle,rektide/webpush-away-deck,hartmamt/builder-talk