rails s -e beta
=> Booting Puma
=> Rails 5.0.3 application starting in beta on http://0.0.0.0:3000
=> Run `rails server -h` for more startup options
Puma starting in single mode...
* Version 3.8.2 (ruby 2.3.0-p0), codename: Sassy Salamander
* Min threads: 5, max threads: 5
* Environment: beta
* Listening on tcp://0.0.0.0:3000