* Remove Kubelet `/etc/iscsi` and `iscsiadm` host mounts that
were added on bare-metal, since these no longer work on either
Fedora CoreOS or Flatcar Linux with newer `iscsiadm`
* These special mounts on bare-metal date back to #350 which
added them to provide a way to use iSCSI in Kubernetes v1.10
* Today, storage should be handled by external CSI providers
which handle different storage systems, which doesn't rely
on Kubelet storage utils
Close#907
* CoreOS Container Linux was deprecated in v1.18.3
* Continue transitioning docs and modules from supporting
both CoreOS and Flatcar "variants" of Container Linux to
now supporting Flatcar Linux and equivalents
Action Required: Update the Flatcar Linux modules `source`
to replace `s/container-linux/flatcar-linux`. See docs for
examples