Add a rake task to export a project's email list (#2855)
Add a rake task to export a project's email list (#2855)

* Add a rake task to export a project's email list

* Fix typo

* Use task arguments

* Fix syntax

* Perform async

camallen/Panoptes,camallen/Panoptes,zooniverse/Panoptes,camallen/Panoptes,zooniverse/Panoptes,zooniverse/Panoptes,camallen/Panoptes,zooniverse/Panoptes