Remove deprecation warnings when running actor tests (#3563)

* remove deprecation warnings when running actor tests

* replacing logger.warn with logger.warning

* Update worker.py

* Update policy_client.py

* Update compression.py

python/ray/actor.py

@@ -216,7 +216,7 @@ class ActorMethod(object):
         return self._remote(args, kwargs)
 
     def _submit(self, args, kwargs, num_return_vals=None):
-        logger.warn(
+        logger.warning(
             "WARNING: _submit() is being deprecated. Please use _remote().")
         return self._remote(
             args=args, kwargs=kwargs, num_return_vals=num_return_vals)
@@ -338,7 +338,7 @@ class ActorClass(object):
                 num_cpus=None,
                 num_gpus=None,
                 resources=None):
-        logger.warn(
+        logger.warning(
             "WARNING: _submit() is being deprecated. Please use _remote().")
         return self._remote(
             args=args,
@@ -679,7 +679,7 @@ class ActorHandle(object):
             # If the worker is a driver and driver id has changed because
             # Ray was shut down re-initialized, the actor is already cleaned up
             # and we don't need to send `__ray_terminate__` again.
-            logger.warn(
+            logger.warning(
                 "Actor is garbage collected in the wrong driver." +
                 " Actor id = %s, class name = %s.", self._ray_actor_id,
                 self._ray_class_name)