Remove mistral from the plan_undeploy workflows

This change removes the `stack_management.py` workflow file. This file
is being deleted because it is unused since we converted the overcloud
delete workbook.

Story: 2007212
Task: 38418

Change-Id: I8adf62fce31ecd69464c429d5988c8f171bb640f
Signed-off-by: Kevin Carter <kecarter@redhat.com>

tripleoclient/workflows/stack_management.py

@@ -1,47 +0,0 @@
-# Copyright 2017 Red Hat, Inc.
-# All Rights Reserved.
-#
-# Licensed under the Apache License, Version 2.0 (the "License"); you may
-# not use this file except in compliance with the License. You may obtain
-# a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
-# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
-# License for the specific language governing permissions and limitations
-# under the License.
-from __future__ import print_function
-
-from tripleoclient.exceptions import InvalidConfiguration
-from tripleoclient.workflows import base
-
-
-def plan_undeploy(clients, plan):
-    """Undeploy the plan and deletes the stack named in the workflow_input.
-
-    :param workflow_client: Workflow client
-    :param plan: Name or ID of plan to delete
-    """
-
-    workflow_client = clients.workflow_engine
-    tripleoclient = clients.tripleoclient
-
-    workflow_input = {
-        'container': plan
-    }
-
-    with tripleoclient.messaging_websocket() as ws:
-        execution = base.start_workflow(
-            workflow_client,
-            'tripleo.deployment.v1.undeploy_plan',
-            workflow_input=workflow_input
-        )
-
-        for payload in base.wait_for_messages(workflow_client, ws, execution):
-            status = payload['status']
-            if status == 'RUNNING':
-                continue
-            if status != 'SUCCESS':
-                raise InvalidConfiguration(payload['message'])