[docs] [issue11468] Improve unittest basic example in the doc

Ezio Melotti <ezio.melotti@gmail.com> added the comment: The patch includes only assertEqual, assertTrue, and assertRaises and, except a s/functions/methods/ in the first line, looks good to me. ---------- stage: needs patch -> commit review versions: -Python 3.1 _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue11468> _______________________________________