Fix lack of space between functions

Somehow this passed through the gate and now it is
causing related failures, so fix it so that those other
failures will not happen.

Change-Id: Idb046b0e4e23af49c947a80cf6f77fef3a9ec0c8

taskflow/persistence/models.py

@@ -63,6 +63,7 @@ def _format_shared(obj, indent):
                                       getattr(obj, attr_name)))
     return lines
 
+
 def _is_all_none(arg, *args):
     if arg is not None:
         return False