Added Supported Python version 3.7

Author: smtakeda

setup.py

@@ -102,6 +102,7 @@
         'Programming Language :: Python :: 3.4',
         'Programming Language :: Python :: 3.5',
         'Programming Language :: Python :: 3.6',
+        'Programming Language :: Python :: 3.7',
 
         'Topic :: Database',
         'Topic :: Software Development',