[Test] Remove unused centos-7

Change-Id: I471e96c8d57100765dc1745037b1917720a1aeac
diff --git a/packer/vars/centos-7.json b/packer/vars/centos-7.json
deleted file mode 100644
index 5e6d1c8..0000000
--- a/packer/vars/centos-7.json
+++ /dev/null
@@ -1,8 +0,0 @@
-{
-  "source_ami_filter_name": "*CentOS Linux 7*HVM*",
-  "source_ami_filter_owner": "679593333241",
-  "ssh_user": "centos",
-
-  "distro": "CentOS 7",
-  "cloud_user_data": "provision/rh-user_data.sh"
-}