Remove __version__ from __all__ in openml\__init__.py (#903)

* remove __version__ from __all__ in init

* Add comment for flake8 test

Author: Rong-Inspur

openml/__init__.py

@@ -46,7 +46,7 @@
 from .setups import OpenMLSetup, OpenMLParameter
 
 
-from .__version__ import __version__
+from .__version__ import __version__  # noqa: F401
 
 
 def populate_cache(task_ids=None, dataset_ids=None, flow_ids=None,
@@ -114,7 +114,6 @@ def populate_cache(task_ids=None, dataset_ids=None, flow_ids=None,
     'study',
     'utils',
     '_api_calls',
-    '__version__',
 ]
 
 # Load the scikit-learn extension by default