Fix set_rate integration test

[willprice]

    def test_set_rate(self):
        self.assertAlmostEqual(1.0, self.player.rate(), _RATE_DP)
        new_rate = 0.5

        self.player.set_rate(new_rate)
        sleep(0.2)

Fails with AssertionError: 0.5 != 1.0 within 2 places

tests/integration/test.py

[willprice]

Fixed in 7445bdd