Created Newsletter as a Suscribible
added suscribible_decorator and newsletter_decorator, with the method param_key
Migration files belong to engine, and not to the dummy app
hound, don't fuck us with schema!!
It's a module, not a decorator -> its name shouldn't be SuscribibleDecorator, but Decorators::Suscribible
Better explanation of what I'm testing
Warnings removed:

spec/models/suscribir/suscripcion_sync_send_grid_observer_spec.rb:48: warning: toplevel constant ENV_CONFIG referenced by Dummy::Application::ENV_CONFIG
(14 times like this)
unhounding quotes
Merge pull request #24 from Soluciones/adding-newsletters

Adding newsletters