Add copyright headers to MAAS repo.

Change-Id: Ib1adb7115ee571765d55ce7fa043ae361ed9485e
diff --git a/roles/head-node/templates/compute-node-vars.yml.j2 b/roles/head-node/templates/compute-node-vars.yml.j2
index 0ece477..4658e4e 100644
--- a/roles/head-node/templates/compute-node-vars.yml.j2
+++ b/roles/head-node/templates/compute-node-vars.yml.j2
@@ -1,3 +1,21 @@
+
+{#
+Copyright 2017-present Open Networking Foundation
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+#}
+
+
 {% if compute_node.password is defined and compute_node.password != omit %}
 password_compute_node: '{{ compute_node.password }}'
 {% endif %}