Add header in AudioKitCore.
Add header in AudioKitCore.

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