class Airbrake::Rails::Railties::MiddlewareTie

exist in Rails 5 anymore.
Insert after DebugExceptions, since ConnectionManagement doesn't
Avoid the warning about deprecated strings.

def tie_rails_5_or_above
  @middleware.insert_after(
    ActionDispatch::DebugExceptions,
    Airbrake::Rack::Middleware,
  )
end