changed To Use AFNetworking 2.0.x

AFNetworking 2.0 doesn't fly with Orbiter. 

My first commit to the pull just changed the version dependency to use 1.x. Then, I decided to just rewrite it for AFN 2.0 since I'm rolling with the 2.x version in my project. 

If you don't want to use my pull req to make it 2.x compatible, you should change up the podspec at a minimum because it defaults to the latest version of AFNetworking.