Update django version used for testing

tox.ini

@@ -6,7 +6,7 @@ envlist = django, flake, coverage
 usedevelop = True
 basepython = python3
 deps =
-    django: Django>=4.1,<4.2
+    django: Django>=5.1,<5.2
     ofxparse
 commands =
     python manage.py test {posargs:silverstrike}