The clone service is not mocked by default

Some services are not mocked by default, so getting the default service
provider was returning a real instance, and setting a Returns on it does
not make NSubstitute happy.

Author: shana

src/UnitTests/GitHub.App/Services/RepositoryCreationServiceTests.cs

@@ -16,7 +16,9 @@ public class TheCreateRepositoryMethod : TestBaseClass
         [Fact]
         public void CreatesRepositoryOnlineViaApiAndThenClonesIt()
         {
-            var provider = Substitutes.ServiceProvider;
+            var cloneService = Substitutes.RepositoryCloneService;
+            var provider = Substitutes.GetServiceProvider(cloneService);
+
             var newRepository = new NewRepository("octokit.net");
             var repository = new TestRepository("octokit.net", "https://github.com/octokit/octokit.net");
             var account = Substitute.For<IAccount>();
@@ -25,7 +27,6 @@ public void CreatesRepositoryOnlineViaApiAndThenClonesIt()
             var apiClient = Substitute.For<IApiClient>();
             apiClient.CreateRepository(newRepository, "octokit", false)
                 .Returns(Observable.Return(repository));
-            var cloneService = provider.GetRepositoryCloneService();
             cloneService.CloneRepository("https://github.com/octokit/octokit.net", "octokit.net", @"c:\dev")
                 .Returns(Observable.Return(Unit.Default));
             var creator = provider.GetRepositoryCreationService();