I have an app that requires iOS 9.1 that I am ready to TestFlight, but when I try to submit the build to TestFlight I get a bunch of errors saying that the SDK version is invalid and the maximum allowed version is 9.0. I could have sworn I saw in the TestFlight news like a week ago that 9.1 apps could now be tested with external testers, but that message has since disappeared. Do I have to wait until the GM for Xcode 7.1 and iOS 9.1 is released before I can test with external testers?