Convert it to SwiftPackageManager

Author: DaniSpenda

Package.swift

@@ -0,0 +1,29 @@
+// swift-tools-version:5.3
+import PackageDescription
+
+let package = Package(
+    name: "Spring",
+    platforms: [
+        .iOS(.v8),
+        .tvOS(.v11)
+    ],
+    products: [
+        .library(
+            name: "Spring",
+            targets: ["Spring"]
+        ),
+    ],
+    targets: [
+        .target(
+            name: "Spring",
+            path: "Spring",
+            exclude: ["Info.plist"],
+            sources: ["."],
+            resources: [
+                // iOS resources
+                .process("*.xib"),
+                .process("../SpringApp/*.xcassets")
+            ]
+        )
+    ]
+)