remove flake8 errors

Author: knikure

tests/unit/test_sklearn.py

@@ -17,7 +17,7 @@
 import os
 import pytest
 
-from mock import Mock, ANY
+from mock import Mock
 from mock import patch
 
 from sagemaker.fw_utils import UploadedCode

tests/unit/test_xgboost.py

@@ -19,7 +19,6 @@
 
 from mock import Mock
 from mock import patch
-from mock import ANY
 from packaging.version import Version