Add SPM support, bump mac version to 10.13, ios version to 11

Unfortunately simd support is only available from iOS 11 and macOS 10.13

.gitignore

@@ -17,3 +17,4 @@ DerivedData
 *.ipa
 *.xcuserstate
 .DS_Store
+contents.xcworkspacedata

DominantColor.podspec

@@ -9,8 +9,8 @@ Pod::Spec.new do |spec|
 	spec.source_files = 'DominantColor/Shared/*.{swift,h,m}'
 	spec.requires_arc = true
 	spec.frameworks = ['GLKit', 'GameKit']
-	spec.ios.deployment_target = '9.0'
-	spec.osx.deployment_target = '10.11'
+	spec.ios.deployment_target = '11.0'
+	spec.osx.deployment_target = '10.13'
 	spec.ios.frameworks = 'UIKit'
 	spec.osx.frameworks = 'Cocoa'
 	spec.swift_versions = ['5.0']

Package.swift

@@ -0,0 +1,28 @@
+// swift-tools-version:5.0
+
+/**
+ *  DominantColor
+ *  Copyright (c) Indragie Karunaratne 2021
+ *  See LICENSE file.
+ */
+
+import PackageDescription
+
+let package = Package(
+    name: "DominantColor",
+    platforms: [
+       .macOS(.v10_13),
+       .iOS(.v11),
+       .tvOS(.v11)
+    ],
+    products: [
+        .library(name: "DominantColor", targets: ["DominantColor"]),
+        .library(name: "DominantColor_Dynamic", type: .dynamic, targets: ["DominantColor"]),
+    ],
+    targets: [
+        .target(
+            name: "DominantColor",
+            path: "DominantColor/Shared"
+        ),
+    ]
+)