Swift: Update to package manager 5.1

swift/Tests/GildedRoseTests/XCTestManifests.swift

@@ -0,0 +1,9 @@
+import XCTest
+
+#if !canImport(ObjectiveC)
+public func allTests() -> [XCTestCaseEntry] {
+    return [
+        testCase(GildedRoseTests.allTests),
+    ]
+}
+#endif

swift/Tests/LinuxMain.swift

@@ -1,7 +1,7 @@
-@testable import GildedRoseTestSuit
-
 import XCTest
 
-XCTMain([
-     testCase(GildedRoseTests.allTests),
-])
+import GildedRoseTests
+
+var tests = [XCTestCaseEntry]()
+tests += GildedRoseTests.allTests()
+XCTMain(tests)

swift/Tests/swiftTests/GildedRoseTests.swift

@@ -1,18 +0,0 @@
-@testable import GildedRose
-import XCTest
-
-class GildedRoseTests: XCTestCase {
-
-    func testFoo() {
-        let items = [Item(name: "foo", sellIn: 0, quality: 0)]
-        let app = GildedRose(items: items);
-        app.updateQuality();
-        XCTAssertEqual("fixme", app.items[0].name);
-    }
-
-    static var allTests : [(String, (GildedRoseTests) -> () throws -> Void)] {
-        return [
-            ("testFoo", testFoo),
-        ]
-    }
-}