Address mypy issue

Change-Id: I21e7ae48cdc90731e4d83c8d214975a6d965c4c9
Signed-off-by: Andriy Kurilin <andr.kurilin@gmail.com>

rally_openstack/task/scenarios/vm/vmtasks.py

@@ -28,7 +28,7 @@ from rally.task import utils as rally_utils
 from rally.utils import sshutils
 
 from rally_openstack.common import consts
-from rally_openstack.common.services import heat
+from rally_openstack.common.services.heat import main as heat
 from rally_openstack.task import scenario
 from rally_openstack.task.scenarios.cinder import utils as cinder_utils
 from rally_openstack.task.scenarios.vm import utils as vm_utils
@@ -322,9 +322,9 @@ class RuncommandHeat(vm_utils.VMScenario):
         parameters["key_name"] = keypair["name"]
         network = self.context["tenant"]["networks"][0]
         parameters["router_id"] = network["router_id"]
-        self.stack = heat.main.Stack(self, self.task,
-                                     template, files=files,
-                                     parameters=parameters)
+        self.stack = heat.Stack(
+            self, self.task, template, files=files, parameters=parameters
+        )
         self.stack.create()
         for output in self.stack.stack.outputs:
             if output["output_key"] == "gate_node":

tests/unit/task/scenarios/vm/test_vmtasks.py

@@ -269,7 +269,7 @@ class VMTasksTestCase(test.ScenarioTestCase):
         fake_stack = mock.Mock()
         fake_stack.stack.outputs = [{"output_key": "gate_node",
                                      "output_value": "ok"}]
-        mock_heat.main.Stack.return_value = fake_stack
+        mock_heat.Stack.return_value = fake_stack
         context = {
             "user": {"keypair": {"name": "name", "private": "pk"},
                      "credential": mock.MagicMock()},