'Resets the atari game, clears the state buffer.'

def get_initial_state(self):

    self.state_buffer = deque()
    x_t = self.env.reset()
    x_t = self.get_preprocessed_frame(x_t)
    s_t = np.stack([x_t for i in range(self.action_repeat)], axis=0)
    for i in range((self.action_repeat - 1)):
        self.state_buffer.append(x_t)
    return s_t
