determine when key was last used

[PatrickJS]

It would be great to see when a key was last used and where (#14) so we can revoke keys that our employees aren't using.

At the same time I would like to opt into envkey "health checks" on certain intervals (24-48hrs unless the server restarted within that time) that way I can see a log of either server restarted and requested envkey or the server is still up. This will allow the client to send up metadata with the key so we know it's being used.

The idea here is to eventually have auto expire keys or to make sure to revoke keys that are just not used.

[danenania]

Yep, access logs for keys are in the works.

The health check idea is good too -- I think sending periodic email warnings when a server hasn't loaded the latest version could definitely be helpful.