Provide reminder/follow for jobs.

Currently, when people visit a job there is no collection of data. This is a potential problem for when the conditions of a given position that has not really captured interest may change/improve. At the moment there isn't a way to reach out to those only-visitors and let them know that they may want to revisit the offer in case it's a better fit for them now.

Proposal: Add a "Keep me updated on this job" option where people can add their email and then be potentially invited.