docs/design/resource_dep: Rebuild after kube-core removal

Adds ClusterK8sIO from e2dc955 (pkg/asset: add ClusterK8sIO,
machines.Worker assets, 2018-10-15, #468), Master from 586ad45
(pkg/asset: Add asset for Master machines, 2018-10-18, #491).  Removes
KubeCoreOperator from c9b0e2f (manifests: stop using kube core
operator, 2018-10-08, #420).

Generated with:

  $ openshift-install graph | dot -Tsvg >docs/design/resource_dep.svg

using:

  $ dot -V
  dot - graphviz version 2.30.1 (20170916.1124)