Add tox envs for Django 2.2, 3.1 and 3.2 and Python 3.9

Author: sastred

setup.py

@@ -53,12 +53,16 @@
         'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',
         'Programming Language :: Python :: 3.8',
+        'Programming Language :: Python :: 3.9',
         'Framework :: Django',
         'Framework :: Django :: 1.9',
         'Framework :: Django :: 1.10',
         'Framework :: Django :: 1.11',
         'Framework :: Django :: 2.0',
         'Framework :: Django :: 2.1',
+        'Framework :: Django :: 2.2',
         'Framework :: Django :: 3.0',
+        'Framework :: Django :: 3.1',
+        'Framework :: Django :: 3.2',
     ]
 )

tox.ini

@@ -17,9 +17,23 @@ envlist =
     py35-dj21
     py36-dj21
     py37-dj21
+    py35-dj22
+    py36-dj22
+    py37-dj22
+    py38-dj22
+    py39-dj22
     py36-dj30
     py37-dj30
     py38-dj30
+    py39-dj30
+    py36-dj31
+    py37-dj31
+    py38-dj31
+    py39-dj31
+    py36-dj32
+    py37-dj32
+    py38-dj32
+    py39-dj32
 skip_missing_interpreters = true
 
 
@@ -32,7 +46,10 @@ deps =
     dj111: Django>=1.11,<2.0
     dj20: Django>=2.0,<2.1
     dj21: Django>=2.1,<2.2
+    dj22: Django>=2.2,<2.3
     dj30: Django>=3.0,<3.1
+    dj31: Django>=3.1,<3.2
+    dj32: Django>=3.1,<3.2
 commands=
     coverage run --rcfile={toxinidir}/.coveragerc {toxinidir}/setup.py test
 	coverage report --omit=*test*