https://casatwy.com/modulization_in_action.html
https://guides.cocoapods.org/syntax/podspec.html#group_build_settings
製做podspec
http://www.jianshu.com/p/ddc2490bff9f
製做私有庫html
https://www.raywenderlich.com/65964/create-a-framework-for-iosios
iOS構建frameworkide