Added swift package manageer support

Author: ekazaev

Package.swift

@@ -0,0 +1,29 @@
+// swift-tools-version:5.1
+
+import PackageDescription
+
+let package = Package(
+    name: "ChatLayout",
+    platforms: [
+        .iOS(.v12)
+    ],
+    products: [
+        .library(
+            name: "ChatLayout",
+            targets: ["ChatLayout"]
+        )
+    ],
+    targets: [
+        .target(
+            name: "ChatLayout",
+            dependencies: [],
+            path: "ChatLayout/Classes"
+        ),
+        .testTarget(
+            name: "ChatLayoutTests",
+            dependencies: ["ChatLayout"],
+            path: "Example/Tests"
+        )
+    ],
+    swiftLanguageVersions: [.v5]
+)