release date done right #1334

Set release badge to update itself automatically whenever a new version is released
Signed-off-by: NStarlord <starlord@zilliz.com>

README.md

@@ -5,8 +5,7 @@
 ![LICENSE](https://img.shields.io/badge/license-Apache--2.0-brightgreen)
 ![Language](https://img.shields.io/github/languages/count/milvus-io/milvus)
 ![GitHub top language](https://img.shields.io/github/languages/top/milvus-io/milvus)
-![Last Release](https://img.shields.io/badge/release-v0.6.0-yellowgreen)
-![Release_date](https://img.shields.io/badge/release%20date-December-yellowgreen)
+![GitHub release (latest by date)](https://img.shields.io/github/v/release/milvus-io/milvus)
 
 [![Build Status](http://internal.zilliz.com:18080/jenkins/job/milvus-ci/job/master/badge/icon)](http://internal.zilliz.com:18080/jenkins/job/milvus-ci/job/master/)
 [![CII Best Practices](https://bestpractices.coreinfrastructure.org/projects/3563/badge)](https://bestpractices.coreinfrastructure.org/projects/3563)