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.
Prefer Token - we might have to support a Kerberos Keytab or client certs and I'd want both of those to work equally well.

In fact, I'm almost positive we'll get asked to support both client certs and token at the same time, and kerberos and token at the same time.  So SecretTypeKubernetesToken would be my preferred choice.