Ensure authtoken installs python-memcached before services start

The keystone::resources::authtoken defined resource type installs
python-memcached, which should be available when services start.

This ensures that all configuration and package installation for
authtoken middleware are completed before config step completes, to
ensure that requirement.

Change-Id: I8f2df1c5881473ca7937bdb26954ce566569788a

manifests/keystone/authtoken.pp

@@ -279,4 +279,6 @@ class aodh::keystone::authtoken(
       service_type                   => $service_type,
       interface                      => $interface;
   }
+
+  Keystone::Resource::Authtoken['aodh_config'] -> Anchor['aodh::config::end']
 }