Add pywin32 for Windows platform (#70)

Author: JarryShaw

setup.py

@@ -92,6 +92,9 @@ def run(self):
           "argparse>=1.1",
           "future",
       ],
+      extras_require={
+          ':sys_platform == "win32"': ['pywin32'],
+      },
       test_suite="tests",
       cmdclass={
           "generate": GenerateThriftCommand,