Version 2.0.0 with main features: Decalarative API and Combine adapta…

…bility

Fixed update of os version to 12 unexpectedly

fixed updated version to iOS 9.0 inseted of iOS 12.0

Some improves

Fixed a bug where BlockAOperation didn't cancel when canceling it in …

…a group operation

some improve in ResultableOperaitons

Fixed a memory leak in URLSessionDataTaskOperation

updated to 1.0.4

framework for tvos osx and watchos released

Some fixes added