Develop - ordering as cocoapods

[southfox]

Hi,

This is a very nice Alert I'm using in my project, I would like to recommend to structure the project as CocoaPods compatible that should pass all the validations of the command:

pod lib lint SweetAlert.podspec

Let me know if you are interested in this PR. If not I'll continue with my fork anyway.

Thanks for the good work. I'm working in this pod to add AppleWatch and TVOS versions.

Keep up the good work.

Thanks, J.