[travis] try to build docker images again (#10412)
[travis] try to build docker images again (#10412)


ray-project/ray,pcmoritz/ray-1,ray-project/ray,pcmoritz/ray-1,richardliaw/ray,ray-project/ray,robertnishihara/ray,pcmoritz/ray-1,richardliaw/ray,richardliaw/ray,robertnishihara/ray,pcmoritz/ray-1,pcmoritz/ray-1,pcmoritz/ray-1,ray-project/ray,robertnishihara/ray,pcmoritz/ray-1,ray-project/ray,richardliaw/ray,robertnishihara/ray,ray-project/ray,ray-project/ray,robertnishihara/ray,robertnishihara/ray,robertnishihara/ray,richardliaw/ray,ray-project/ray,pcmoritz/ray-1,richardliaw/ray,robertnishihara/ray,robertnishihara/ray,richardliaw/ray,richardliaw/ray