Add Python 3.9 to tox

Author: ulgens

.github/workflows/tests.yml

@@ -9,7 +9,7 @@ jobs:
       max-parallel: 4
       matrix:
         django: ["2.2", "3.0", "3.1"]
-        python-version: ["3.6", "3.7", "3.8"]
+        python-version: ["3.6", "3.7", "3.8", "3.9"]
 
     steps:
     - uses: actions/checkout@v1

tox.ini

@@ -1,13 +1,14 @@
 [tox]
 envlist =
-    py{36,37,38}-django{22,30,31,main},
+    py{36,37,38,39}-django{22,30,31,main},
     black,flake8
 
 [gh-actions]
 python =
     3.6: py36
     3.7: py37
     3.8: py38
+    3.9: py39
 
 [gh-actions:env]
 DJANGO =
@@ -35,13 +36,13 @@ deps =
 commands = {posargs:py.test --cov=graphene_django graphene_django examples}
 
 [testenv:black]
-basepython = python3.8
+basepython = python3.9
 deps = -e.[dev]
 commands  =
     black --exclude "/migrations/" graphene_django examples setup.py --check
 
 [testenv:flake8]
-basepython = python3.8
+basepython = python3.9
 deps = -e.[dev]
 commands =
     flake8 graphene_django examples setup.py