Supporting iOS version current minus one

Author: aure

Package.swift

@@ -6,7 +6,7 @@ import PackageDescription
 let package = Package(
     name: "SoundpipeAudioKit",
     platforms: [
-        .macOS(.v10_14), .iOS(.v11), .tvOS(.v11)
+        .macOS(.v10_14), .iOS(.v13), .tvOS(.v13)
     ],
     products: [
         // Products define the executables and libraries a package produces, and make them visible to other packages.