MNT: Python version classifiers in setup.py

setup.py

@@ -102,10 +102,9 @@ setup(
         'Development Status :: 3 - Alpha',
         'Intended Audience :: Developers',
         'License :: OSI Approved :: Apache Software License',
-        'Programming Language :: Python :: 2.7',
-        'Programming Language :: Python :: 3.4',
         'Programming Language :: Python :: 3.5',
         'Programming Language :: Python :: 3.6',
+        'Programming Language :: Python :: 3.7',
         'Topic :: Software Development :: Libraries :: Python Modules'],
 
     packages=packages,