'Cron should ignore the helpful articles.'

def test_caching_helpful(self):

    r = _make_backdated_revision(90)
    for x in range(0, 3):
        _add_vote_in_past(r, 1, 3)
    for x in range(0, 2):
        _add_vote_in_past(r, 0, 3)
    cache_most_unhelpful_kb_articles()
    eq_(0, self.redis.llen(self.REDIS_KEY))
