Have a different worker name for each thread.

This makes each thread create their own git repo so threads don't
compete and cause race conditions

Change-Id: Ifaf1faf153d9b26a0ff302b00603573b04205b04
diff --git a/tests/test_worker_manager.py b/tests/test_worker_manager.py
index 93acbb1..11fc960 100644
--- a/tests/test_worker_manager.py
+++ b/tests/test_worker_manager.py
@@ -36,7 +36,8 @@
         self.config['zuul_server']['gearman_port'] = self.gearman_server.port
 
         self.task = FakeRealDbUpgradeRunner(self.config,
-                                            self.config['plugins'][0], self)
+                                            self.config['plugins'][0],
+                                            'test-worker-1', self)
         self.tasks = dict(FakeRealDbUpgradeRunner_worker=self.task)
 
         self.gearman_manager = FakeGearmanManager(self.config,