Support for Oauth2 v2.x

[JacobMarq]

Thank you so much for putting this valuable gem together.

Are there plans to update the gemspec to use OAuth2 v2.x? Recently after installing this gem I saw "You have installed oauth2 version 1.4.10, which is EOL."

[dleidert]

Maybe it is enough to just relax the dependency? Have you tried that?