Deprecate enable_mistral and enable_zaqar

... because support for Mistral[1] and Zaqar[2] were both deprecated.

[1] 47ab368caf2566f30dd55138c76ec97fb716370d
[2] d00943a58a76dc7194e1e722c050e76ef671483e

Change-Id: Id0286c75eef31dca8e720e36d82d9f3ec10f5f1c

releasenotes/notes/deprecate-mistral-and-zaqar-aee14846fe3662d7.yaml

@@ -0,0 +1,6 @@
+---
+features:
+  - |
+    The ``enable_mistral`` parameter and the ``enable_zaqar`` parameter in
+    undercloud/standalone deployment have been deprecated and will be removed
+    in a future release.

tripleoclient/config/standalone.py

@@ -74,6 +74,9 @@ class StandaloneConfig(BaseConfig):
                         ),
             cfg.BoolOpt('enable_mistral',
                         default=mistral,
+                        deprecated_for_removal=True,
+                        deprecated_reason=('Support for the mistral service '
+                                           'has been deprecated.'),
                         help=_('Whether to enable the mistral service.')),
             cfg.BoolOpt('enable_nova',
                         default=nova,
@@ -100,6 +103,9 @@ class StandaloneConfig(BaseConfig):
                         ),
             cfg.BoolOpt('enable_zaqar',
                         default=zaqar,
+                        deprecated_for_removal=True,
+                        deprecated_reason=('Support for the zaqar service '
+                                           'has been deprecated.'),
                         help=_('Whether to enable the zaqar service.')),
             cfg.BoolOpt('enable_neutron',
                         default=neutron,