Even though it is mentioned in the link - https://developer.apple.com/ios/submit/ that all new iOS apps and updates submitted to the App Store must be built with the iOS 11 SDK using Xcode 9 from July 2018, i am not able to upload a build to testflight from 5/22/2018.
Please see below the error i am seeing - ERROR ITMS-90725: "SDK Version Issue. This app was built with the iOS '9.3' SDK. All new iOS apps submitted to the App Store must be built with the iOS '11.0' SDK or later, included in Xcode [9.0] or later. Please update Xcode and rebuild your app."
Any work around would be really helpful. Please let me know if you are facing similar issues?