dummy environment doesn't exist anymore
fix typo in email configuration
use `airbrake` instead of `airbrake_user_attributes`
deliver airbrake errors async

with `girl_friday`. See https://github.com/airbrake/airbrake/wiki/Using-Airbrake-asynchronously
use `airbrake_javascript_notifier`
bugfix: order scope name. Fixes #26

correct is `eager_loaded`