v3.4.0

• Avoid including Rails url_helpers into Preview class when they're not defined.

  Richard Macklin

• Allow instrumentation to be automatically included in Server-Timing headers generated by Rails. To enable this set the config config.use_deprecated_instrumentation_name = false. The old key !render.view_component is deprecated: update ActiveSupport::Notification subscriptions to render.view_component.

  Travis Gaff