Automatically reassign public tasks which have been open for N days

Currently, when a user opens a public task in the task workspace, that task is automatically reassigned to them. If the user never closes this task, it may stay open forever. This would be fine for a tutorial task but not a citizen science task! So, if we ever implement citizen science tasks, we need some kind of namespace setting for reassigning stale tasks back to the task bucket they came from. This would likely have to be implemented as a cron job in the queue.

https://www.npmjs.com/package/node-cron