Support manual source for ml results

Closes #26 (closed)

arkindex_worker/worker.py

@@ -18,6 +18,8 @@ from arkindex_worker import logger
 from arkindex_worker.models import Element
 from arkindex_worker.reporting import Reporter
 
+MANUAL_SLUG = "manual"
+
 
 class BaseWorker(object):
     def __init__(self, description="Arkindex Base Worker"):
@@ -604,5 +606,11 @@ class ElementsWorker(BaseWorker):
         # transcriptions have worker_version_id but elements have worker_version
         elif "worker_version_id" in ml_result and ml_result["worker_version_id"]:
             return self.get_worker_version_slug(ml_result["worker_version_id"])
+        elif "worker_version" in ml_result and ml_result["worker_version"] is None:
+            return MANUAL_SLUG
+        elif (
+            "worker_version_id" in ml_result and ml_result["worker_version_id"] is None
+        ):
+            return MANUAL_SLUG
         else:
             raise ValueError(f"Unable to get slug from: {ml_result}")