Allow oslo.log to work on non-linux platforms

Especially needed for all the HyperV work on windows.

Depends-On: I1a0a2dacbefa548296a6cfef1663ea9d48253c0c
Change-Id: Ifcc854e6eb6f4d0e575d1489f0d00f3339705e0b

oslo_log/tests/unit/test_log.py

@@ -684,8 +684,9 @@ class FastWatchedFileHandlerTestCase(BaseTestCase):
         self._config()
         logger = log._loggers[None].logger
         self.assertEqual(1, len(logger.handlers))
+        from oslo_log import watchers
         self.assertIsInstance(logger.handlers[0],
-                              handlers.FastWatchedFileHandler)
+                              watchers.FastWatchedFileHandler)
 
     def test_log(self):
         log_path = self._config()