fix unit test mock issue

Author: japdubengsub

tests/tests_pytorch/loggers/test_all.py

@@ -108,7 +108,8 @@ def log_metrics(self, metrics, step):
     if logger_class == CometLogger:
         logger.experiment.id = "foo"
         logger._comet_config.offline_directory = None
-        logger.experiment.project_name = "bar"
+        logger._project_name = "bar"
+        logger.experiment.get_key.return_value = "SOME_KEY"
 
     if logger_class == NeptuneLogger:
         logger._retrieve_run_data = Mock()