Adding tox

tox.ini

@@ -0,0 +1,25 @@
+# tox (https://tox.readthedocs.io/) is a tool for running tests
+# in multiple virtualenvs. This configuration file will run the
+# test suite on all supported python versions. To use it, "pip install tox"
+# and then run "tox" from this directory.
+
+[pytest]
+DJANGO_SETTINGS_MODULE=tests.test_project.settings
+addopts = --doctest-modules -ra -l --tb=short --show-capture=log --color=yes
+testpaths = admin_confirm
+
+[tox]
+envlist =
+    {py38, py39, py3}-dj{31,30,22,19,17}-postgres
+
+[testenv]
+whitelist_externals = pytest
+deps =
+    djmaster: https://github.com/django/django/archive/master.tar.gz
+    dj31: Django>=3.1,<3.2
+    dj30: Django>=3.0,<3.1
+    dj22: Django>=2.2,<2.3
+    dj19: Django>=1.9,<2.2
+    dj17: Django>=1.7,<1.9
+commands =
+    pytest