signal backend, app cleanup

app/celery.py

@@ -0,0 +1,16 @@
+import os
+
+from celery import Celery
+
+os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'app.settings')
+
+app = Celery('app')
+
+# Using a string here means the worker doesn't have to serialize
+# the configuration object to child processes.
+# - namespace='CELERY' means all celery-related configuration keys
+#   should have a `CELERY_` prefix.
+app.config_from_object('django.conf:settings', namespace='CELERY')
+
+# Load task modules from all registered Django app configs.
+app.autodiscover_tasks()