Improved type safety, local auth support, and better error handling

Package.swift

@@ -1,16 +1,15 @@
-// swift-tools-version:5.2
+// swift-tools-version: 5.10
 // The swift-tools-version declares the minimum version of Swift required to build this package.
 
 import PackageDescription
 
 let package = Package(
-  name: "KeychainKit",
-  platforms: [.iOS(.v8)],
-  products: [
-    .library(name: "KeychainKit", targets: ["KeychainKit"]),
-  ],
-  dependencies: [],
-  targets: [
-    .target(name: "KeychainKit", dependencies: [])
-  ]
+    name: "KeychainKit",
+    platforms: [.macOS(.v10_15), .iOS(.v13)],
+    products: [
+        .library(name: "KeychainKit", targets: ["KeychainKit"]),
+    ],
+    targets: [
+        .target(name: "KeychainKit")
+    ]
 )