* master:
  Handle interrupts correctly for ASIO synchronous reads and writes. (ray-project#1929)
  [DataFrame] Adding read methods and tests (ray-project#1712)
  Allow task_table_update to fail when tasks are finished. (ray-project#1927)
  [rllib] Contribute DDPG to RLlib (ray-project#1877)
  [xray] Workers blocked in a `ray.get` release their resources (ray-project#1920)
  Raylet task dispatch and throttling worker startup (ray-project#1912)
  [DataFrame] Eval fix (ray-project#1903)
  [tune] Polishing docs (ray-project#1846)
  [tune] [rllib] Automatically determine RLlib resources and add queueing mechanism for autoscaling (ray-project#1848)
  Preemptively push local arguments for actor tasks (ray-project#1901)
  [tune] Allow fetching pinned objects from trainable functions (ray-project#1895)
  Multithreading refactor for ObjectManager. (ray-project#1911)
  Add slice functionality (ray-project#1832)
  [DataFrame] Pass read_csv kwargs to _infer_column (ray-project#1894)
  Addresses missed comments from multichunk object transfer PR. (ray-project#1908)
  Allow numpy arrays to be passed by value into tasks (and inlined in the task spec). (ray-project#1816)
  [xray] Lineage cache requests notifications from the GCS about remote tasks (ray-project#1834)
  Fix UI issue for non-json-serializable task arguments. (ray-project#1892)
  Remove unnecessary calls to .hex() for object IDs. (ray-project#1910)
  Allow multiple raylets to be started on a single machine. (ray-project#1904)

# Conflicts:
#	python/ray/rllib/__init__.py
#	python/ray/rllib/dqn/dqn.py