Do not implicitly set up rack-timeout middleware
Do not implicitly set up rack-timeout middleware

By requiring `rack-timeout`, `Rack::Timeout` is automatically added to the middleware of a Rails application. 

See https://github.com/heroku/rack-timeout#rails-apps

This leads to unexpected behavior. When a user adds a non-standard `Rack-Timeout` to the middleware stack herself, she ends up with `Rack-Timeout` added twice. Worse, the configuration added automatically is the standard configuration which might differ from the one added manually in user land. Worst case comes to show when a user configures a `service_timeout` greater than the standard one.
looker/raven-ruby,getsentry/raven-ruby