Add-sshkey: ensure that ssh home directory exists

Some images might not have pre-created that directory, hence failing the task.
This simple step will prevent that.

Change-Id: Id2b63e84ef047f02127772c4d45b55ec360436f8

roles/add-sshkey/tasks/main.yaml

@@ -1,3 +1,9 @@
+- name: Ensure that ssh home directory exists
+  file:
+    path: "~/.ssh"
+    state: directory
+    mode: 0700
+
 - name: Write out ssh key
   copy:
     dest: "~/.ssh/id_rsa"