Add support for Swift Package Manager

.gitignore

@@ -37,4 +37,5 @@ DerivedData
 *.hmap
 *.ipa
 *.xcuserstate
+.build
 

Package.swift

@@ -0,0 +1,5 @@
+import PackageDescription
+
+let package = Package(
+    name: "Swifter"
+)

Tests/LinuxMain.swift

@@ -0,0 +1,6 @@
+import XCTest
+@testable import SwifterTests
+
+XCTMain([
+     testCase(SwifterTests.allTests),
+])

Tests/SwifterTests/SwifterTests.swift

@@ -0,0 +1,17 @@
+import XCTest
+@testable import Swifter
+
+class SwifterTests: XCTestCase {
+    func testExample() {
+        // This is an example of a functional test case.
+        // Use XCTAssert and related functions to verify your tests produce the correct results.
+        XCTAssertEqual(Swifter().text, "Hello, World!")
+    }
+
+
+    static var allTests : [(String, (SwifterTests) -> () throws -> Void)] {
+        return [
+            ("testExample", testExample),
+        ]
+    }
+}