[Core] Multi-tenancy: enable multi-tenancy by default (#10570)

* Add new job in Travis to enable multi-tenancy

* fix

* Update .bazelrc

* Update .travis.yml

* fix test_job_gc_with_detached_actor

* fix test_multiple_downstream_tasks

* fix lint

* Enable multi-tenancy by default

* Kill idle workers in FIFO order

* Update test

* minor update

* Address comments

* fix some cases

* fix test_remote_cancel

* Address comments

* fix after merge

* remove kill

* fix worker_pool_test

* fix java test timeout

* fix test_two_custom_resources

* Add a delay when killing idle workers

* fix test_worker_failure

* fix test_worker_failed again

* fix DisconnectWorker

* update test_worker_failed

* Revert some python tests

* lint

* address comments

python/ray/tests/test_multinode_failures.py

@@ -63,7 +63,11 @@ def test_worker_failed(ray_start_workers_separate_multinode):
     time.sleep(0.1)
     # Kill the workers as the tasks execute.
     for pid in pids:
-        os.kill(pid, SIGKILL)
+        try:
+            os.kill(pid, SIGKILL)
+        except OSError:
+            # The process may have already exited due to worker capping.
+            pass
         time.sleep(0.1)
     # Make sure that we either get the object or we get an appropriate
     # exception.