Set up initial structure

.swift-version

@@ -0,0 +1 @@
+4.0

Package.swift

@@ -0,0 +1,19 @@
+// swift-tools-version:4.0
+import PackageDescription
+
+#if os(macOS) || os(iOS) || os(watchOS) || os(tvOS)
+let dependencies: [Package.Dependency] = []
+#else
+let dependencies: [Package.Dependency] = [.package(url: "https://github.com/IBM-Swift/CZlib.git", .exact("0.1.2"))]
+#endif
+
+let package = Package(
+    name: "GzipMiddleware",
+    products: [
+        .library(name: "GzipMiddleware", targets: ["GzipMiddleware"])
+    ],
+	dependencies: dependencies,
+    targets: [
+        .target(name: "GzipMiddleware"),
+    ]
+)