Rename Uninferable and instantiate_class, fix broken tests, improve

testing.

* Rename YES to Uninferable
* Rename instanciate_class to instantiate_class.
* Use six in test_namedtuple_advanced_inference.
* Fix test_file_from_module failure on PyPy.
* Add enum34 to unittest_brain.
* Add unittest_brain dependencies tox.ini.

1 files changed, 6 insertions, 2 deletions

diff --git a/astroid/util.py b/astroid/util.py
index 20c44d7..439d967 100644
--- a/astroid/util.py
+++ b/astroid/util.py
@@ -33,10 +33,10 @@ def reraise(exception):
 
 
 @object.__new__
-class YES(object):
+class Uninferable(object):
     """Special inference object, which is returned when inference fails."""
     def __repr__(self):
-        return 'YES'
+        return 'Uninferable'
 
     def __getattribute__(self, name):
         if name == 'next':
@@ -66,3 +66,7 @@ def proxy_alias(alias_name, node_type):
                  {'__class__': object.__dict__['__class__'],
                   '__instancecheck__': _instancecheck})
     return proxy(lambda: node_type)
+
+
+# Backwards-compatibility aliases
+YES = Uninferable