Add checkpointing feature for custodian. This allows recovery from jobs.
Add checkpointing feature for custodian.
This allows recovery from jobs.

specter119/custodian,alberthxf/custodian,materialsproject/custodian,materialsproject/custodian,materialsproject/custodian,specter119/custodian,xhqu1981/custodian,specter119/custodian,davidwaroquiers/custodian