[Autoscaler] Run resource demand scheduler in CI (#9945)

* .

* .

ci/travis/ci.sh

@@ -155,6 +155,7 @@ test_python() {
       -python/ray/tests:test_object_manager
       -python/ray/tests:test_projects
       -python/ray/tests:test_ray_init  # test_redis_port() seems to fail here, but pass in isolation
+      -python/ray/tests:test_resource_demand_scheduler
       -python/ray/tests:test_stress  # timeout
       -python/ray/tests:test_stress_sharded  # timeout
       -python/ray/tests:test_webui

python/ray/tests/BUILD

@@ -41,6 +41,7 @@ py_test_module_list(
     "test_output.py",
     "test_placement_group.py",
     "test_reconstruction.py",
+    "test_resource_demand_scheduler.py",
     "test_reference_counting_2.py",
     "test_reference_counting.py",
     "test_stress.py",

python/ray/tests/test_resource_demand_scheduler.py

@@ -146,11 +146,12 @@ def test_get_instances_respects_max_limit():
 class AutoscalingTest(unittest.TestCase):
     def setUp(self):
         NODE_PROVIDERS["mock"] = \
-            lambda: (None, self.create_provider)
+            lambda config: self.create_provider
         self.provider = None
         self.tmpdir = tempfile.mkdtemp()
 
     def tearDown(self):
+        self.provider = None
         del NODE_PROVIDERS["mock"]
         shutil.rmtree(self.tmpdir)
         ray.shutdown()