fix: adjust Ray test script for Ray 0.6.5 (#781)

Author: laurenyu

tests/data/ray_cartpole/train_ray.py

@@ -5,7 +5,7 @@
 from ray.tune.logger import pretty_print
 
 # Based on https://github.com/ray-project/ray/blob/master/doc/source/rllib-training.rst#python-api
-ray.init(redirect_output=False, redirect_worker_output=False)
+ray.init(log_to_driver=False)
 config = ppo.DEFAULT_CONFIG.copy()
 config["num_gpus"] = int(os.environ.get("SM_NUM_GPUS", 0))
 checkpoint_dir = os.environ.get("SM_MODEL_DIR", '/Users/nadzeya/gym')