Kilo oslo.messaging added heartbeating support for RabbitMQ
connections. This patch adds support for this in Puppet modules
by managing the oslo_messaging_rabbit/heartbeat_timeout_threshold
and oslo_messaging_rabbit/heartbeat_rate settings.
Closes-bug: 1467667
Change-Id: I985d081c86975c5b216f6346cbd9a368dd0d33d3