remove some old versionchanged and versionadded directives
diff --git a/Doc/library/difflib.rst b/Doc/library/difflib.rst
index db4bd3a..585fa74 100644
--- a/Doc/library/difflib.rst
+++ b/Doc/library/difflib.rst
@@ -401,8 +401,7 @@
 
    If no blocks match, this returns ``(alo, blo, 0)``.
 
-   .. versionchanged:: 2.6
-      This method returns a :term:`named tuple` ``Match(a, b, size)``.
+   This method returns a :term:`named tuple` ``Match(a, b, size)``.
 
 
 .. method:: SequenceMatcher.get_matching_blocks()