revert dask/ to master

Author: cjac

dask/test_dask.py

@@ -56,13 +56,16 @@ def _run_dask_test_script(self, name, script):
     )
     def test_dask(self, configuration, instances, runtime):
 
+        if self.getImageVersion() < pkg_resources.parse_version("2.0"):
+            self.skipTest("Not supported in pre-2.0 images")
+
         metadata = None
         if runtime:
             metadata = "dask-runtime={}".format(runtime)
 
         self.createCluster(configuration,
                            self.INIT_ACTIONS,
-                           machine_type='n1-highmem-8',
+                           machine_type='n1-standard-16',
                            metadata=metadata,
                            timeout_in_minutes=20)