Modif the check of metadata value

arkindex_worker/worker/metadata.py

@@ -152,9 +152,10 @@ class MetaDataMixin(object):
                 metadata.get("name"), str
             ), "name shouldn't be null and should be of type str"
 
-            assert metadata.get("value") and isinstance(
-                metadata.get("value"), (str, float, int)
-            ), "value shouldn't be null and should be of type (str or float or int)"
+            value = metadata.get("value")
+            assert value is not None and isinstance(
+                value, (str, float, int) and 0 <= value <= 1
+            ), "value shouldn't be null and should be of type (str or float or int) in [0..1] range"
 
             assert metadata.get("entity_id") is None or isinstance(
                 metadata.get("entity_id"), str