Fixed DestroyService spec to actually test if removal was successful

spec/services/projects/destroy_service_spec.rb

@@ -15,8 +15,9 @@ describe Projects::DestroyService, services: true do
   shared_examples 'deleting the project' do
     it 'deletes the project' do
       expect(Project.unscoped.all).not_to include(project)
-      expect(Dir.exist?(path)).to be_falsey
-      expect(Dir.exist?(remove_path)).to be_falsey
+
+      expect(project.gitlab_shell.exists?(project.repository_storage_path, path + '.git')).to be_falsey
+      expect(project.gitlab_shell.exists?(project.repository_storage_path, remove_path + '.git')).to be_falsey
     end
   end