Bug Fix on the Relation class instanciation

lodel/leapi/datahandlers/references/relation.py

     # @param datahandler_args dict
     # @param reference EmField
     # @param kwargs
-    def __init__(self, datahandler, datahandler_args, reference, **kwargs):
-
+    def __init__(self, **kwargs):
         # Data Handler
-        data_handler_class = FieldDataHandler.from_name(datahandler)
-        self.data_handler = data_handler_class(**datahandler_args)
+        data_handler = kwargs['data_handler_kwargs']['data_handler']
+        data_handler_args = kwargs['data_handler_kwargs']
+        data_handler_class = FieldDataHandler.from_name(data_handler)
+        self.data_handler = data_handler_class(**data_handler_args)
 
         # Reference
-        self.backref_ref = reference
+        self.backref_ref = kwargs['data_handler_kwargs']['backreference']
 
         super().__init__(**kwargs)

test_em.py

                         data_handler = 'varchar',
                         group = editorial_person_group
 )
-"""
+
 person.new_field(   'linked_texts',
                     display_name = {
                         'eng': 'Linked texts',
                     },
                     group = editorial_person_group,
 )
+
 text.new_field( 'linked_persons',
                 display_name = {
                     'eng': 'Linked persons',
                 },
                 group = editorial_person_group,
 )
-"""