Add openstackclient installation to the client class

The repo is inside the openstackclient plugin commands[1].

[1]https://docs.openstack.org/python-openstackclient/latest/cli/plugin-commands.html

Change-Id: Iaea6f4c1df928c273ef358dcfaf95a49963bee20

manifests/client.pp

@@ -25,4 +25,6 @@ class designate::client (
     tag    => 'openstack',
   }
 
+  include '::openstacklib::openstackclient'
+
 }

releasenotes/notes/add-openstackclient-client-91871f75080a05b6.yaml

@@ -0,0 +1,3 @@
+---
+features:
+  - Add openstackclient installation to the client class.

spec/classes/designate_client_spec.rb

@@ -21,6 +21,8 @@ describe 'designate::client' do
           :tag    => 'openstack'
         )
       end
+
+      it { is_expected.to contain_class('openstacklib::openstackclient') }
     end
 
     context 'with custom package name' do