Breathing new life into this repo in 2019

[TimOliver]

Hi folks! I just came across this library when I was looking to add OAuth integration into one of my Objective-C projects.

It looks like the definitive OAuth 2 manager for Objective-C, however, with some glaring bugs that have pending pull requests, it looks like no one from the original team has been able to maintain it for a little while.

Is anyone from the original team still around? I'd love to help get those pending PRs merged if possible. :)