update README

jasonjoo2010 · jasonjoo2010 · commit 3ea8e7a56e92 · 2020-06-22T18:07:32.000+08:00
diff --git a/README.md b/README.md
@@ -148,14 +148,10 @@ Benefit of abstracting of storage kinds of backend can be easily supported:
 
 * Memory(Only for local testing or local usage scenario)
 * Redis
-
-And there are also several backends in roadmap:
-
+* Etcdv2
+* Etcdv3
+* Database
 * Zookeeper
-* MySQL
-* Mongodb
-* etcd
-* nacos
 
 ## Extending
 
