Return 'class' as BaseName.type of _PseudoTreeNameClass (fix #1578)

jedi/inference/gradual/base.py

@@ -306,6 +306,8 @@ class _PseudoTreeNameClass(Value):
     this class. Essentially this class makes it possible to goto that `Tuple`
     name, without affecting anything else negatively.
     """
+    api_type = u'class'
+
     def __init__(self, parent_context, tree_name):
         super(_PseudoTreeNameClass, self).__init__(
             parent_context.inference_state,