Merge pull request #4 from mohpor/SPM

Added SPM Support

Author: Coeur

Package.swift

@@ -0,0 +1,16 @@
+// swift-tools-version:5.0
+import PackageDescription
+
+let package = Package(
+    name: "CollectionViewCenteredFlowLayout",
+    products: [
+        .library(name: "CollectionViewCenteredFlowLayout", targets: ["CollectionViewCenteredFlowLayout"])
+    ],    
+    targets: [
+        .target(
+            name: "CollectionViewCenteredFlowLayout",
+            path: "CollectionViewCenteredFlowLayout"
+        )
+    ],
+    swiftLanguageVersions: [.v5]
+)