Construct package references directly, rather than with legacy convenience initializer

Author: mattt

Tests/PackageRegistryTests/RegistryManagerTests.swift

@@ -25,7 +25,7 @@ final class RegistryManagerTests: XCTestCase {
     }
 
     func testDiscoverPackageRegistry() {
-        let package = PackageReference(identity: "github.com/mona/LinkedList".lowercased(), path: "/LinkedList")
+        let package: PackageReference = .remote(name: "LinkedList", url: "https://github.com/mona/LinkedList")
         let expectation = XCTestExpectation(description: "discover package registry")
 
         RegistryManager.discover(for: package) { result in
@@ -38,7 +38,7 @@ final class RegistryManagerTests: XCTestCase {
     }
 
     func testFetchVersions() {
-        let package = PackageReference(identity: "github.com/mona/LinkedList".lowercased(), path: "/LinkedList")
+        let package: PackageReference = .remote(name: "LinkedList", url: "https://github.com/mona/LinkedList")
         let expectation = XCTestExpectation(description: "discover package registry")
 
         RegistryManager.discover(for: package) { result in
@@ -66,7 +66,7 @@ final class RegistryManagerTests: XCTestCase {
     }
 
     func testFetchManifest() {
-        let package = PackageReference(identity: "github.com/mona/LinkedList".lowercased(), path: "/LinkedList")
+        let package: PackageReference = .remote(name: "LinkedList", url: "https://github.com/mona/LinkedList")
         let expectation = XCTestExpectation(description: "discover package registry")
 
         RegistryManager.discover(for: package) { result in
@@ -107,7 +107,7 @@ final class RegistryManagerTests: XCTestCase {
     }
 
     func testDownloadSourceArchive() {
-        let package = PackageReference(identity: "github.com/mona/LinkedList".lowercased(), path: "/LinkedList")
+        let package: PackageReference = .remote(name: "LinkedList", url: "https://github.com/mona/LinkedList")
         let expectation = XCTestExpectation(description: "discover package registry")
 
         RegistryManager.discover(for: package) { result in