print 'NLU server' when running NLU only
print 'NLU server' when running NLU only

rasa run with an nlu model would print "running rasa core server" which
was confusing, since there is no differentiation beyond the name of the
model this message will now print NLU if 'nlu' is in the model name

RasaHQ/rasa_nlu,RasaHQ/rasa_nlu,RasaHQ/rasa_nlu