Use secrets.yml and .env instead of secret_token.rb

Does this look like a good way to set up secret_key_base? I followed advice from:

http://guides.rubyonrails.org/upgrading_ruby_on_rails.html#config-secrets-yml 

https://github.com/bkeepers/dotenv-deployment#capistrano-3 

There is no need to define a per-environment variable because you are not supposed to add this per-enviroment values to the repo. You just keep 1 .env file and that's the one loaded by your application. The  .env you add to the repo will contain development settings that should allow any of your team to use.  But, in the production environment, you override the .env files with the right values because it is assumed only authorized people can access the production environment.