add vtnAPIVersion to tosca resources

Change-Id: Ic40d92faad431c71b1e3e9b326d85a5cab935280
diff --git a/xos/tosca/resources/vtnservice.py b/xos/tosca/resources/vtnservice.py
index 2a5738f..b8ccd59 100644
--- a/xos/tosca/resources/vtnservice.py
+++ b/xos/tosca/resources/vtnservice.py
@@ -12,4 +12,4 @@
 class XOSVTNService(XOSService):
     provides = "tosca.nodes.VTNService"
     xos_model = VTNService
-    copyin_props = ["view_url", "icon_url", "enabled", "published", "public_key", "versionNumber", 'privateGatewayMac', 'localManagementIp', 'ovsdbPort', 'sshPort', 'sshUser', 'sshKeyFile', 'mgmtSubnetBits', 'xosEndpoint', 'xosUser', 'xosPassword']
+    copyin_props = ["view_url", "icon_url", "enabled", "published", "public_key", "versionNumber", 'privateGatewayMac', 'localManagementIp', 'ovsdbPort', 'sshPort', 'sshUser', 'sshKeyFile', 'mgmtSubnetBits', 'xosEndpoint', 'xosUser', 'xosPassword', 'vtnAPIVersion']