Summary: Ref T5833. Since these will no longer be bound specifically to users, bring them to a more central location.
Test Plan:
- Edited SSH keys.
- Ran `bin/ssh-auth` and `bin/ssh-auth-key`.
Reviewers: btrahan
Reviewed By: btrahan
Subscribers: epriestley
Maniphest Tasks: T5833
Differential Revision: https://secure.phabricator.com/D10791
