WIP.  Robot account proposal.

In a rough state but putting out for comment.

There has been considerable discussion about the general problem of secret distribution for docker and kubernetes.
While that is a great goal, I think it will take some time.
In the shorter term, I want to be able to just distribute secrets for access to the kubernetes API.
This proposal just focuses on that.

That problem is important to solve because:
  - it lets us run scheduler and controller-manager via /pods
  - lets users write their own services, like cron, build controllers, etc, more easily.
  - gets us closer to self-hosting.
Could get very chatty.  Other options are to bind the secret in at pod binding time like service env vars, and require the pod to be recreated to get updated (which is what we're doing in theory for other updates).  If you bind the secret at start time you don't need to make Kubelet calls.  That would mean though that there may be people that wish to consume the bound pods REST API endpoint that don't deserve access to secrets - but we could handle that with authz filtering of fields if we had to.