Ft facebook login with devise

I think that for this is better  to put
config.omniauth :facebook, Rails.application.config.facebook_key, Rails.application.config.facebook_secret

And on the config/environments folder you set the respective credencials depending if it is test, development, production.
you define on each evironment file:
config.facebook_key = "948016475213340"
config.facebook_secret = 083cd9f114b5a219a52f9a30125e18d5