Add dependencies and supported platforms

Package.swift

@@ -1,28 +1,24 @@
-// swift-tools-version: 5.6
-// The swift-tools-version declares the minimum version of Swift required to build this package.
+// swift-tools-version: 5.5
 
 import PackageDescription
 
 let package = Package(
     name: "Push-API",
+    platforms: [
+       .macOS(.v10_15),
+       .iOS(.v13)
+    ],
     products: [
-        // Products define the executables and libraries a package produces, and make them visible to other packages.
         .library(
             name: "Push-API",
             targets: ["Push-API"]),
     ],
     dependencies: [
-        // Dependencies declare other packages that this package depends on.
-        // .package(url: /* package url */, from: "1.0.0"),
+        .package(url: "https://github.com/kylebrowning/APNSwift.git", from: "4.0.0"),
     ],
     targets: [
-        // Targets are the basic building blocks of a package. A target can define a module or a test suite.
-        // Targets can depend on other targets in this package, and on products in packages this package depends on.
         .target(
             name: "Push-API",
-            dependencies: []),
-        .testTarget(
-            name: "Push-APITests",
-            dependencies: ["Push-API"]),
+            dependencies: [.product(name: "APNSwift", package: "APNSwift")])
     ]
 )