Call cancel() on deinit in case machine is still running.
Call cancel() on deinit in case machine is still running.

luzefeng/SwiftTask,msdgwzhy6/SwiftTask,iosyoujian/SwiftTask,ReactKit/SwiftTask,msdgwzhy6/SwiftTask,luzefeng/SwiftTask,ReactKit/SwiftTask,msdgwzhy6/SwiftTask,iosyoujian/SwiftTask,marinehero/SwiftTask,marinehero/SwiftTask,ReactKit/SwiftTask,luzefeng/SwiftTask,marinehero/SwiftTask,marinehero/SwiftTask,luzefeng/SwiftTask,iosyoujian/SwiftTask,iosyoujian/SwiftTask,msdgwzhy6/SwiftTask