Update README.md

README.md

@@ -8,7 +8,7 @@ microservices, cloud native and container-based (Docker, K8s, Mesos) architectur
 Underlying technology is a distributed tracing system.
 
 [![Build Status](https://travis-ci.org/apache/incubator-skywalking.svg?branch=master)](https://travis-ci.org/apache/incubator-skywalking)
-[![Coverage Status](https://coveralls.io/repos/github/apache/incubator-skywalking/badge.svg?branch=master&u=1)](https://coveralls.io/github/apache/incubator-skywalking?branch=master)
+[![Twitter URL](https://img.shields.io/twitter/url/http/shields.io.svg?style=social)](https://twitter.com/AsfSkyWalking)
 [![Join the chat at https://gitter.im/sky-walking/Lobby](https://badges.gitter.im/openskywalking/Lobby.svg)](https://gitter.im/openskywalking/Lobby)
 [![OpenTracing-1.x Badge](https://img.shields.io/badge/OpenTracing--1.x-enabled-blue.svg)](http://opentracing.io)