Make available via CocoaPods

[p0deje]

First of all, let me say thank you for that project - it really helped me to implement a custom keyboard navigation for my NSMenu within an hour. Even though I'm just a beginner in Swift and Cocoa.

For now, I just copy-pasted your class and it works perfectly. However, I wonder if you consider making it a library that can be installed via CocoaPods (Carthage)? In this case, it would be even easier to install, use and keep it up to date.