Add registry and cleanup files

apps/sources/cleanup.py

@@ -0,0 +1,9 @@
+from __future__ import absolute_import
+
+
+def cleanup():
+    from .models import StagingFolder, WebForm, SourceTransformation
+
+    StagingFolder.objects.all().delete()
+    WebForm.objects.all().delete()
+    SourceTransformation.objects.all().delete()

apps/sources/registry.py

@@ -0,0 +1,6 @@
+from __future__ import absolute_import
+
+from .cleanup import cleanup
+
+
+cleanup_functions = [cleanup]