Update setup.py

setup.py

@@ -22,6 +22,7 @@ setuptools.setup(
         "Programming Language :: Python :: 3.6",
         "Programming Language :: Python :: 3.7",
         "Programming Language :: Python :: 3.8",
+        "Programming Language :: Python :: 3.9",
         "License :: OSI Approved :: MIT License",
         "Operating System :: OS Independent",
     )