update tutorial (#342)
update tutorial (#342)


robertnishihara/ray,Wapaul1/ray,stephanie-wang/ray,stephanie-wang/ray,amplab/ray,atumanov/ray,ray-project/ray,stephanie-wang/ray,stephanie-wang/ray,robertnishihara/ray,ray-project/ray,Wapaul1/ray,pcmoritz/ray-1,robertnishihara/ray,alanamarzoev/ray,richardliaw/ray,pcmoritz/ray-1,richardliaw/ray,Wapaul1/ray,atumanov/ray,amplab/ray,richardliaw/ray,pcmoritz/ray-1,stephanie-wang/ray,ray-project/ray,pcmoritz/ray-1,richardliaw/ray,richardliaw/ray,Wapaul1/ray,atumanov/ray,stephanie-wang/ray,stephanie-wang/ray,robertnishihara/ray,robertnishihara/ray,pcmoritz/ray-1,robertnishihara/ray,alanamarzoev/ray,atumanov/ray,atumanov/ray,stephanie-wang/ray,robertnishihara/ray,ujvl/ray-ng,amplab/ray,pcmoritz/ray-1,ray-project/ray,atumanov/ray,atumanov/ray,robertnishihara/ray,ray-project/ray,pcmoritz/ray-1,richardliaw/ray,Wapaul1/ray,richardliaw/ray,alanamarzoev/ray,alanamarzoev/ray,Wapaul1/ray,stephanie-wang/ray,ray-project/ray,amplab/ray,robertnishihara/ray,ray-project/ray,richardliaw/ray,alanamarzoev/ray,ujvl/ray-ng,ujvl/ray-ng,ujvl/ray-ng,atumanov/ray,alanamarzoev/ray,ray-project/ray,pcmoritz/ray-1