hacked in oauth2 support via access_token => Net::OAuth2::AccessToken

Heya, tried to find a good way to contact you besides a pull request, but there doesn't seem to be any kind of messaging system on github.
Anyways, I added OAuth2 access token support with https://metacpan.org/source/MARKOV/Net-OAuth2-0.53/lib/Net/OAuth2/AccessToken.pm#L5

I've been using it for 2 weeks with this script: https://github.com/ediblenergy/pdd/blob/master/script/greader.pl
and nothing unexpected or weird so far!
If you're interested, I could help out with a test or some docs for it or whatever.