add test for polymorphic respond_with case
add test for polymorphic respond_with case

gpr/responders,pravi/responders,telekomatrix/responders,telekomatrix/responders,muthhus/responders,muthhus/responders,plataformatec/responders,pravi/responders,plataformatec/responders,plataformatec/responders,gpr/responders