Feature request - single user mode

[DarrenS]

It would be a handy feature for us to be able to lock Vault into "single user mode", such that only 'admin' can get in. This would be just like SQL Server single-user mode, and for that matter the same option on most mainframes and UNIX systems. It would be helpful for performing maintenance operations without users trying to log in; should be pretty simple to implement too, I'd think.