* Move openshift_router to openshift_hosted role which will eventually
contain registry, metrics and logging.
* Adds option for specifying an openshift_hosted_router_certificate
cert and key pair.
* Removes dependency on node label variables and retrieves the node
list from the API s.t. this role can be applied to any cluster with
existing nodes. I've added an openshift_hosted playbook that occurs
after node install to account for this.
* Infrastructure nodes are selected using
openshift_hosted_router_selector which is based on deployment type
by default; openshift-enterprise -> "region=infra" and online ->
"type=infra".