Migrates to Swift + Swinft Package Manager

Package.swift

@@ -0,0 +1,14 @@
+// swift-tools-version:5.2
+// The swift-tools-version declares the minimum version of Swift required to build this package.
+
+import PackageDescription
+
+let package = Package(
+    name: "YoutubePlayer",
+    platforms: [.iOS(.v13)],
+    products: [ .library(name: "YoutubePlayer", targets: ["YoutubePlayer"]) ],
+    targets: [
+        .target(name: "YoutubePlayer"),
+        .testTarget(name: "youtube-ios-player-helperTests", dependencies: ["YoutubePlayer"]),
+    ]
+)