We were able to submit builds to iTunes Connect for internal beta testing just fine with Xcode 6.X. Now that we have upgraded our Swift project to Xcode 7 and Swift 2, we have been getting the "Invalid Swift Support" error:
Invalid Swift Support - The files libswiftCoreAudio.dylib,
libswiftCoreMedia.dylib, libswiftCoreData.dylib, libswiftAVFoundation.dylib
don’t match /Payload/AppName.app/Frameworks/libswiftCoreAudio.dylib,
/Payload/AppName.app/Frameworks/libswiftCoreMedia.dylib,
/Payload/AppName.app/Frameworks/libswiftCoreData.dylib,
/Payload/AppName.app/Frameworks/libswiftAVFoundation.dylib. Make sure the
files are correct, rebuild your app, and resubmit it. Don’t apply
post processing to /Payload/AppName.app/Frameworks/libswiftCoreAudio.dylib,
/Payload/AppName.app/Frameworks/libswiftCoreMedia.dylib,
/Payload/AppName.app/Frameworks/libswiftCoreData.dylib,
/Payload/AppName.app/Frameworks/libswiftAVFoundation.dylib