Added testing against Django 5.1.

Author: carltongibson

setup.cfg

@@ -24,6 +24,7 @@ classifiers =
     Framework :: Django
     Framework :: Django :: 4.2
     Framework :: Django :: 5.0
+    Framework :: Django :: 5.1
     Topic :: Internet :: WWW/HTTP
 
 [options]

tox.ini

@@ -2,6 +2,7 @@
 envlist =
     py{38,39,310,311}-dj42
     py{310,311,312}-dj50
+    py{310,311,312}-dj51
     py{310,311,312}-djmain
     qa
 
@@ -11,7 +12,8 @@ commands =
     pytest -v {posargs}
 deps =
     dj42: Django>=4.2,<5.0
-    dj50: Django>=5.0rc1,<5.1
+    dj50: Django>=5.0,<5.1
+    dj51: Django>=5.1a1,<5.2
     djmain: https://github.com/django/django/archive/main.tar.gz
 
 [testenv:qa]