Adding podspec. 

Already pushed a podspec to the Cocoapods/Specs repo. I thought if you guys would to have one local as well.

I also rewrote the tests to use XCTest instead and use a 'local' cocoapod-based workspace with a guard.rb file. 
But that's too much of a change and my assumption is that it's not for you, but let me know if I'm wrong.