'Allow unicode strings for "ids" parameter in Python 2 (##1905)'

def test_parametrize_and_id_unicode(self):

    def func(x):
        pass
    metafunc = self.Metafunc(func)
    metafunc.parametrize('x', [1, 2], ids=[u'basic', u'advanced'])
    ids = [x.id for x in metafunc._calls]
    assert (ids == [u'basic', u'advanced'])
