Support the custom field for rfc3442 static routes to the edgeconfig script

Run netprep role on compute servers, with a suitable netplan

Change-Id: I3406d39cbdf733d3a0c1c1e8470f30471a278e60
diff --git a/playbooks/aethercompute-playbook.yml b/playbooks/aethercompute-playbook.yml
index 6bbd776..d88483a 100644
--- a/playbooks/aethercompute-playbook.yml
+++ b/playbooks/aethercompute-playbook.yml
@@ -4,5 +4,6 @@
   hosts: aethercompute
   become: true
   roles:
+    - netprep
     - users
     - docker