OAuth2 Support

[canavese]

As far as I can tell, Xero now requires OAuth2 for API access, which is not supported by this gem. Please correct me if I'm wrong!

[minimul]

No OAuth2 support.

I never got a chance to use this gem on project.

It's a darn good gem though, perhaps you could build out OAuth2?

[canavese]

Thanks for the confirmation. The official xero-ruby gem is 388KB (vs. your 24KB) and feels unwieldy. The xeroizer gem, which is the most popular and which I'm using for now, is better (227KB) and slimmer then xero-ruby.

If I can find some time, I may well figure out the OAuth2 piece and submit a pull request.

Either way, I wanted to provide a paper trail for others who might be evaluating options.