Add deprecate warning to ceilometer::client

With ceilometer api deprecated, we dont need client anymore.
We should encourage using gnocchi, aodh and panko clients
instead.

Change-Id: I53b8fe3c300d3539da2de4a29e9b2b8e432eadc6

manifests/client.pp

@@ -15,6 +15,9 @@ class ceilometer::client (
   include ::ceilometer::deps
   include ::ceilometer::params
 
+  warning('This class is deprecated and will be removed in future releases.
+           Use gnocchi, aodh or panko clients to access data instead.')
+
   package { 'python-ceilometerclient':
     ensure => $ensure,
     name   => $::ceilometer::params::client_package_name,

releasenotes/notes/deprecate-ceilo-client-9613505a11df867b.yaml

@@ -0,0 +1,4 @@
+---
+deprecations:
+  - Deprecate ceilometer::client as api is deprecated. Instead use gnocchi,
+    aodh and panko clients directly to query data.