Fix the logout to use a POST (introduced with Django 4.1)

Also add an handy command to clear Django cache

ram/ram/__init__.py

@@ -1,4 +1,4 @@
 from ram.utils import git_suffix
 
-__version__ = "0.13.3"
+__version__ = "0.13.4"
 __version__ += git_suffix(__file__)

ram/ram/management/commands/purge_cache.py

@@ -0,0 +1,13 @@
+from django.core.cache import cache
+from django.core.management.base import BaseCommand, CommandError
+
+
+class Command(BaseCommand):
+    help = "Clear the application cache"
+
+    def handle(self, *args, **options):
+        try:
+            cache.clear()
+            self.stdout.write(self.style.SUCCESS("Cache cleared"))
+        except Exception:
+            raise CommandError("Cache is not active")