Add SSH key to user "debug" during disk-install phase

* Avoid adding SSH authorized key for user "core" during the disk
install, so that terraform apply cannot SSH until post-install

bare-metal/container-linux/kubernetes/cl/container-linux-install.yaml.tmpl

@@ -32,6 +32,11 @@ storage:
           systemctl reboot
 passwd:
   users:
-    - name: core
+    # Avoid using standard name "core" so terraform apply cannot SSH until post-install.
+    - name: debug
+      create:
+        groups:
+          - sudo
+          - docker
       ssh_authorized_keys:
         - {{.ssh_authorized_key}}

bare-metal/container-linux/pxe-worker/ssh.tf

@@ -1,5 +1,5 @@
 # Secure copy kubeconfig to all nodes to activate kubelet.service
-resource "null_resource" "copy-kubeconfig" {
+resource "null_resource" "copy-secrets" {
   count = "${length(var.worker_names)}"
 
   connection {