Upgrade to common-packer

- Enable builder.json
- Relove unused provision scripts
- Update ci-management-packer-jobs
- Update builder.yaml

Change-Id: I0c9abcd33fd3acb84690863dca966a01731dc64c
Issue-ID: CIMAN-33
Signed-off-by: Jessica Wagantall <jwagantall@linuxfoundation.org>
diff --git a/packer/vars/centos.json b/packer/vars/centos.json
index c5b8c79..366202c 100644
--- a/packer/vars/centos.json
+++ b/packer/vars/centos.json
@@ -1,6 +1,6 @@
 {
   "base_image": "CentOS 7.1611 (2017-01-30) - LF upload",
-  "cloud_user": "centos",
+  "ssh_user": "centos",
   "distro": "CentOS 7",
   "cloud_user_data": "provision/rh-user_data.sh"
 }