bump version to 0.2.1

Author: pzhokhov

setup.py

@@ -33,7 +33,7 @@ def __init__(self, name, sourcedir=''):
         self.sourcedir = os.path.abspath(sourcedir)
 
 setup(name='atari-py',
-      version='0.2.0',
+      version='0.2.1',
       description='Python bindings to Atari games',
       url='https://github.com/openai/atari-py',
       author='OpenAI',