add badge

Author: silentred

README.md

@@ -5,6 +5,7 @@ Toolkit of web API and RPC services
 ![](https://img.shields.io/badge/language-golang-blue.svg)
 ![](https://img.shields.io/badge/license-MIT-000000.svg)
 ![](https://img.shields.io/github/tag/silentred/toolkit.svg)
+[![Go Report Card](https://goreportcard.com/badge/github.com/silentred/toolkit)](https://goreportcard.com/report/github.com/silentred/toolkit)
 [![codebeat badge](https://codebeat.co/badges/644e898b-f0cb-4a05-b701-cdfb790c37e5)](https://codebeat.co/projects/github-com-silentred-toolkit-master)
 [![Codacy Badge](https://api.codacy.com/project/badge/Grade/ae66252a0e4b45719e08037088d07863)](https://www.codacy.com/app/silentred/toolkit?utm_source=github.com&utm_medium=referral&utm_content=silentred/toolkit&utm_campaign=Badge_Grade)