Add casbin into readme.
@@ -110,6 +110,7 @@ Please take a quick gander at the [contribution guidelines](https://github.com/a
*Libraries for implementing authentications schemes.*
* [authboss](https://github.com/go-authboss/authboss) - A modular authentication system for the web. It tries to remove as much boilerplate and "hard things" as possible so that each time you start a new web project in Go, you can plug it in, configure, and start building your app without having to build an authentication system each time.
+* [casbin](https://github.com/hsluoyz/casbin) - An authorization library that supports access control models like ACL, RBAC, ABAC.
* [Go-AWS-Auth](https://github.com/smartystreets/go-aws-auth) - AWS (Amazon Web Services) request signing library.
* [go-jose](https://github.com/square/go-jose) - A fairly complete implementation of the JOSE working group's JSON Web Token, JSON Web Signatures, and JSON Web Encryption specs.
* [go-oauth2-server](https://github.com/RichardKnop/go-oauth2-server) - A standalone, specification-compliant, OAuth2 server written in Golang.
