Bump to 4.8 for Xcode 11 branch
Bump to 4.8 for Xcode 11 branch

adamnemecek/AudioKit,eljeff/AudioKit,eljeff/AudioKit,eljeff/AudioKit,audiokit/AudioKit,adamnemecek/AudioKit,eljeff/AudioKit,audiokit/AudioKit,audiokit/AudioKit,audiokit/AudioKit,adamnemecek/AudioKit,adamnemecek/AudioKit