[docs] Improve unittest basic example in the doc (issue 11468)

[berker.peksag at gmail.com]

http://bugs.python.org/review/11468/diff/2986/Doc/library/unittest.rst
File Doc/library/unittest.rst (right):

http://bugs.python.org/review/11468/diff/2986/Doc/library/unittest.rst#newcode131
Doc/library/unittest.rst:131: self.assertEqual(s.split(), ['hello',
'world'])
I think this is a good example to use assertListEqual.

http://bugs.python.org/review/11468/