add local_sagemaker_session to horovod test (#652)

Author: ChoiByungWook

tests/integ/test_horovod.py

@@ -55,13 +55,14 @@ def test_horovod(sagemaker_session, instance_type, tmpdir):
     [1, 2],
     (2, 1),
     (2, 2)])
-def test_horovod_local_mode(instances, processes, tmpdir):
+def test_horovod_local_mode(sagemaker_local_session, instances, processes, tmpdir):
     output_path = 'file://%s' % tmpdir
 
     estimator = TensorFlow(entry_point=os.path.join(horovod_dir, 'test_hvd_basic.py'),
                            role='SageMakerRole',
                            train_instance_count=2,
                            train_instance_type='local',
+                           sagemaker_session=sagemaker_local_session,
                            py_version=integ.PYTHON_VERSION,
                            script_mode=True,
                            output_path=output_path,