Add a account clenup command.

opentech/apply/users/management/commands/accounts_cleanup.py

+from django.contrib.auth import get_user_model
+from django.core.management.base import BaseCommand
+from django.db import transaction
+
+
+class Command(BaseCommand):
+    help = "1. Mark all accounts that has not logged in after 3 month after creation as inactive. 2. Delete accounts that has never logged in and has no applications"
+
+    @transaction.atomic
+    def handle(self, *args, **options):
+        User = get_user_model()
+        users = User.objects.filter(last_login__isnull=True, groups__isnull=True, applicationsubmission__isnull=True)
+        for user in users:
+            user.is_active = False
+            user.save()