Updated SPM support to modern times.

Author: radianttap

Package.swift

@@ -1,24 +1,27 @@
+// swift-tools-version:5.1
 import PackageDescription
 
-
-#if os(macOS) || os(iOS) || os(watchOS) || os(tvOS)
-let package = Package(
-  name: "JWT",
-  dependencies: [
-    .Package(url: "https://github.com/kylef-archive/CommonCrypto.git", majorVersion: 1),
-  ],
-  exclude: [
-    "Sources/JWT/HMACCryptoSwift.swift",
-  ]
-)
-#else
 let package = Package(
-  name: "JWT",
-  dependencies: [
-    .Package(url: "https://github.com/krzyzanowskim/CryptoSwift.git", majorVersion: 0, minor: 8),
-  ],
-  exclude: [
-    "Sources/JWT/HMACCommonCrypto.swift",
-  ]
+	name: "JWT",
+	platforms: [
+		.iOS(.v12),
+		.tvOS(.v12),
+		.watchOS(.v6)
+	],
+	products: [
+		// Products define the executables and libraries a package produces, and make them visible to other packages.
+		.library(
+			name: "JWT",
+			targets: ["JWT"])
+	],
+	dependencies: [],
+	targets: [
+		.target(
+			name: "JWT",
+			dependencies: [],
+			path: "Sources/JWT",
+			exclude: ["HMACCryptoSwift.swift"]
+		)
+	],
+	swiftLanguageVersions: [.v5]
 )
-#endif