Add timestamp for updates as well.

apigee_sync.go

diff --git a/apigee_sync.go b/apigee_sync.go
index 3fed06a..95ddb9b 100644
--- a/apigee_sync.go
+++ b/apigee_sync.go
@@ -22,6 +22,7 @@
 	req.Header.Add("Authorization", "Bearer "+token)
 	req.Header.Set("apid_instance_id", guuid)
 	req.Header.Set("apid_cluster_Id", gapidConfigId)
+	req.Header.Set("updated_at_time", time.Now().Format(time.RFC3339))
 }
 
 func donehandler(e apid.Event) {
@@ -217,7 +218,7 @@
 	req.Header.Set("apid_instance_id", guuid)
 	req.Header.Set("apid_cluster_Id", gapidConfigId)
 	req.Header.Set("status", "ONLINE")
-	req.Header.Set("created_at", time.Now().Format(time.RFC3339))
+	req.Header.Set("created_at_time", time.Now().Format(time.RFC3339))
 	req.Header.Set("plugin_details", gpgInfo)
 
 	client := &http.Client{}