Deprecate non containerized undercloud

We're deprecating the non containerized undercloud in Rocky, and move
forward with containerized undercloud during the cycle.

Change-Id: Ib23d805e8780191882a8dd09172d4fadef283057

releasenotes/notes/deprecate_instack-e6ffdc2bb886a3c8.yaml

@@ -0,0 +1,5 @@
+---
+deprecations:
+  - |
+    instack-undercloud is deprecated in Rocky cycle and is replaced by
+    the containerized undercloud efforts in python-tripleoclient.

tripleoclient/v1/undercloud.py

@@ -72,6 +72,8 @@ class InstallUndercloud(command.Command):
                     no_validations=no_validations,
                     verbose_level=self.app_args.verbose_level)
         else:
+            self.log.warning('Non-containerized undercloud deployment is '
+                             'deprecated in Rocky cycle.')
             cmd = ["instack-install-undercloud"]
         if parsed_args.dry_run:
             print(' '.join(cmd))
@@ -99,6 +101,8 @@ class UpgradeUndercloud(InstallUndercloud):
             print("Running: %s" % ' '.join(cmd))
             subprocess.check_call(cmd)
         else:
+            self.log.warning('Non-containerized undercloud deployment is '
+                             'deprecated in Rocky cycle.')
             subprocess.check_call(['sudo', 'yum', 'update', '-y',
                                   'instack-undercloud'])
             subprocess.check_call("instack-pre-upgrade-undercloud")