Implement CephX key rotation for Rook's client.admin user.
Admin user rotation is risky, so this has been tested extensively both
in unit tests as well as by manually injecting failures during runtime.
In testing, all failures were able to be recovered by the recovery
routine.
A mutex is also added to help ensure that two simultaneous admin key
rotation processes cannot be running simultaneously for any given
namespace. The mutex is tested in unit tests, and it was verified during
runtime via manual testing.
Signed-off-by: Blaine Gardner <blaine.gardner@ibm.com>
Blaine Gardner