test against python3.9

.github/workflows/python.yml

@@ -37,6 +37,7 @@ jobs:
         - 3.6
         - 3.7
         - 3.8
+        - 3.9
       fail-fast: false
     steps:
     - uses: actions/checkout@v1

setup.py

@@ -46,6 +46,7 @@ setuptools.setup(
         "Programming Language :: Python :: 3.6",
         "Programming Language :: Python :: 3.7",
         "Programming Language :: Python :: 3.8",
+        "Programming Language :: Python :: 3.9",
         "Topic :: Utilities",
     ],
     entry_points={