puma.rb in potassium-2.2.0

- old
+ new

@@ -18,10 +18,10 @@
 
 preload_app!
 
 rackup DefaultRackup
 port ENV.fetch('PORT', 3000)
-environment ENV.fetch("RAILS_ENV", "development")
+environment ENV.fetch("RACK_ENV", "development")
 
 on_worker_boot do
   # Worker specific setup for Rails 4.1+
   # See: https://devcenter.heroku.com/articles/deploying-rails-applications-with-the-puma-web-server#on-worker-boot
   ActiveRecord::Base.establish_connection