add the implementation to the delegate's method (RTagCloudView:didTapOnTagOfIndex:) and pod spec file

today I see your useful share long ago, and I want add it to my project, but I need tap a label function, so  I add the implementation to this delegate's method，and use ARC for this lib.
 I also add a pod spec file, use it more convenient.

=>pod spec file push command:
pod spec lint RTagCloudView.podspec
pod push RTagCloudView.podspec