Adapt rabbitmq module for Fuel

* Add dependency modules: garethr-erlang, nanliu-staging
* Add service_provider param for rabbitmq class
* Fix deprecated usage of rabbitmq::server class to ::rabbitmq
  (nova, cinder, murano, openstack, zabbix, mcollective, mailgun)
* Fix linting
* Fix OS-aware service disabling for pacemaker provider case
* Use config_kernel_variables, config_variables, environment_variables
  params to ensure the same rabbit config as it was before
* Add cluster_partition_handling for nova::rabbitmq and
  openstack::controller
* Adjust debug log_levels for rabbit config as well
* Move custom init scripts for rabbit to nailgun module
* Remove rspecs for custom init scripts for rabbit module as obsoleted

Related blueprint merge-openstack-puppet-modules

Change-Id: I6e631b975c5835d2d6f1984d5a070a45231fe9ab
Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>