dyld: Library not loaded: /System/Library/Frameworks/UserNotifications.framework/UserNotifications
Referenced from: /var/containers/Bundle/Application/B0936ED2-FB82-4487-AE21-A1185AA36EF9/TestUserNotification.app/TestUserNotification
Reason: image not found
Xcode8 引用UserNotifications.framework,在iOS9.3 报错;
高版本Framework不支持低版本手机,改为可选即可