Update Jenkins executors to Ubuntu 18.04

- Upgrade global jjb to v0.57.4
- Upgrade packer to v0.7.0
- Use the Ansible approach to install most required services

Change-Id: I1a56db63e14d847971131eef96828004c6ae4478
diff --git a/packer/provision/local-builder.yaml b/packer/provision/local-builder.yaml
new file mode 100644
index 0000000..8315fa0
--- /dev/null
+++ b/packer/provision/local-builder.yaml
@@ -0,0 +1,6 @@
+# SPDX-FileCopyrightText: 2020 Open Networking Foundation <info@opennetworking.org>
+#
+# SPDX-License-Identifier: LicenseRef-ONF-Member-Only-1.0
+
+---
+- import_playbook: ../provision/baseline.yaml