Add markbates/goth auth library

README.md

@@ -100,6 +100,7 @@ Join us on IRC at **#awesome-go** on freenode [web access](http://webchat.freeno
 * [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.auth](https://github.com/bradrydzewski/go.auth) - Authentication API for Go web applications.
 * [gorbac](https://github.com/mikespook/gorbac) - provides a lightweight role-based access control (RBAC) implementation in Golang.
+* [goth](https://github.com/markbates/goth) - provides a simple, clean, and idiomatic way to use OAuth and OAuth2. Handles multiple provides out of the box.
 * [httpauth](https://github.com/goji/httpauth) - HTTP Authentication middleware.
 * [jwt-go](https://github.com/dgrijalva/jwt-go) - Golang implementation of JSON Web Tokens (JWT).
 * [oauth2](https://github.com/golang/oauth2) - Successor of goauth2. Generic OAuth 2.0 package that comes with JWT, Google APIs, Compute Engine and App Engine support.