Handle invalid data format for pubsub actions
Handle invalid data format for pubsub actions

Ref. SkygearIO/skygear-SDK-JS#27
SkygearIO/skygear-server,SkygearIO/skygear-server,rickmak/skygear-server,rickmak/skygear-server,SkygearIO/skygear-server,rickmak/skygear-server,SkygearIO/skygear-server