WIP: Fix dtype creation fail

Author: mattjala

h5pyd/_hl/h5type.py

@@ -877,7 +877,7 @@ def createDataType(typeItem):
             raise KeyError("no 'field' elements provided")
         subtypes = []
         for field in fields:
-            if isinstance(field, dict):
+            if type(field) is not dict:
                 raise TypeError("Expected dictionary type for field")
             if 'name' not in field:
                 raise KeyError("'name' missing from field")