fix(doc): update notice and open statistic label (#378)

fix(doc): update notice and open statistic label (#378)
diff --git a/NOTICE b/NOTICE
index 85e2dc3..65ebdd0 100644
--- a/NOTICE
+++ b/NOTICE
@@ -1,5 +1,5 @@
 Apache RocketMQ
-Copyright 2016-2019 The Apache Software Foundation
+Copyright 2016-2020 The Apache Software Foundation
 
 This product includes software developed at
 The Apache Software Foundation (http://www.apache.org/).
diff --git a/README.md b/README.md
index fc59306..b7ca531 100644
--- a/README.md
+++ b/README.md
@@ -2,6 +2,10 @@
 [![License](https://img.shields.io/badge/license-Apache%202-4EB1BA.svg)](https://www.apache.org/licenses/LICENSE-2.0.html)
 [![TravisCI](https://travis-ci.org/apache/rocketmq-client-go.svg)](https://travis-ci.org/apache/rocketmq-client-go)
 [![Coverage](https://codecov.io/gh/apache/rocketmq-client-go/branch/native/graph/badge.svg)](https://codecov.io/gh/apache/rocketmq-client-go/branch/native)
+[![GitHub release](https://img.shields.io/badge/release-download-default.svg)](https://github.com/apache/rocketmq-client-go/releases)
+[![Average time to resolve an issue](http://isitmaintained.com/badge/resolution/apache/rocketmq-client-go.svg)](http://isitmaintained.com/project/apache/rocketmq-client-go "Average time to resolve an issue")
+[![Percentage of issues still open](http://isitmaintained.com/badge/open/apache/rocketmq-client-go.svg)](http://isitmaintained.com/project/apache/rocketmq-client-go "Percentage of issues still open")
+![Twitter Follow](https://img.shields.io/twitter/follow/ApacheRocketMQ?style=social)
 
 The RocketMQ Client in pure go, the project is developing, **there is no any guarantee in production environment**. in next versions,
 we will do our best to improve reliability, stability, usability and performance. the API may be changed, and more features will be added.
@@ -10,13 +14,14 @@
 or create a new issue.
 
 - [2.0.0 Production Ready Road map](https://github.com/apache/rocketmq-client-go/issues/57)
-- [The alpha1 feature list](https://github.com/apache/rocketmq-client-go/issues/54)
 
 ----------
 ## Features
-in 2.0.0-alpha1, support:
+in 2.0.0-rc1, support:
 * sending message in synchronous mode
+* sending message in asynchronous mode
 * sending message in oneway mode
+* sending orderly messages
 * consuming message using push model
 
 ----------
diff --git a/changelog b/changelog
deleted file mode 100755
index 8d96e5f..0000000
--- a/changelog
+++ /dev/null
@@ -1,20 +0,0 @@
-version 2.0.0-alpha1
- * basic feature in pure go
- * sending message in synchronous mode
- * sending message in oneway mode
- * consuming message using push model
-
-version 1.2.0
- * support reliable synchronous sending of messages;
- * support reliable orderly sending of messages;
- * support reliable push consumption model;
- * support default cluster consumption;
- * support delayed messages;
- * support reliable pull consumption model;
- * support custom message properties;
- * support message Compression.
- * support oneway sending of messages.
-
-version 1.0.0 @2018.10.29
- * Initialize version of Go client.
-