created additional flag for un-set booleans
created additional flag for un-set booleans

[1,1] = True
[1,0] = False
[0,0] = Un-set

RasaHQ/rasa_nlu,RasaHQ/rasa_core,RasaHQ/rasa_nlu,RasaHQ/rasa_core,RasaHQ/rasa_core,RasaHQ/rasa_nlu