readme: note about k8s 1.5 won't work
fix
@@ -19,6 +19,7 @@ Read [Developer Guide](./doc/dev/developer_guide.md) for setting up development
## Requirements
- Kubernetes 1.4+
+ **Warning**: as of Kubernetes 1.5.2 etcd operator won't well work due to k8s bug: https://github.com/kubernetes/kubernetes/issues/39816 .
- etcd 3.0+
## Namespace
