Added tracker to the Redmine notification plugin
Added tracker to the Redmine notification plugin

Tracker is added as an optional field. If no tracker is supplied, `nil` will be sent.
6wunderkinder/bugsnag-notification-plugins,sharesight/bugsnag-notification-plugins,6wunderkinder/bugsnag-notification-plugins,kstream001/bugsnag-notification-plugins,cagedata/bugsnag-notification-plugins,jacobmarshall/bugsnag-notification-plugins,korealert/bugsnag-notification-plugins,indirect/bugsnag-notification-plugins,korealert/bugsnag-notification-plugins