fix #213, remove obsolete OrderedDict reference

anytree/exporter/dictexporter.py

@@ -23,27 +23,12 @@ class DictExporter:
     >>> s1 = AnyNode(a="sub1", parent=root)
 
     >>> exporter = DictExporter()
-    >>> pprint(exporter.export(root))  # order within dictionary might vary!
+    >>> pprint(exporter.export(root))
     {'a': 'root',
      'children': [{'a': 'sub0',
                    'children': [{'a': 'sub0A', 'b': 'foo'}, {'a': 'sub0B'}]},
                   {'a': 'sub1'}]}
 
-    Pythons dictionary `dict` does not preserve order.
-    :any:`collections.OrderedDict` does.
-    In this case attributes can be ordered via `attriter`.
-
-    >>> from collections import OrderedDict
-    >>> exporter = DictExporter(dictcls=OrderedDict, attriter=sorted)
-    >>> pprint(exporter.export(root))
-    OrderedDict([('a', 'root'),
-                 ('children',
-                  [OrderedDict([('a', 'sub0'),
-                                ('children',
-                                 [OrderedDict([('a', 'sub0A'), ('b', 'foo')]),
-                                  OrderedDict([('a', 'sub0B')])])]),
-                   OrderedDict([('a', 'sub1')])])])
-
     The attribute iterator `attriter` may be used for filtering too.
     For example, just dump attributes named `a`: