Handle the API Server certificates

[xmudrii]

In order to ensure possibility of integration with tools such as helm, so API Servers can be deployed easier, we need to handle API Server certificates.

Initially, this has been planned for Milestone 3, so this is a good time to discuss is the implementation.

We could integrate with, or use part of openshift/service-serving-cert-signer to make generation and rotation easier.

/cc @deads2k @sttts