Add Redfish provider logger

In order to keep the main log clean of Redfish provider messages, we
added new log file and associated logger that can be used by the
Redfish provider.

.rubocop_local.yml

@@ -25,6 +25,7 @@ GlobalVars:
   - $vim_log
   - $websocket_log
   - $nuage_log
+  - $redfish_log
 Rails/Exit:
   Exclude:
   - lib/workers/bin/*

lib/vmdb/loggers.rb

@@ -96,6 +96,7 @@ def self.apply_config(config)
       apply_config_value(config, $lenovo_log,        :level_lenovo)
       apply_config_value(config, $nuage_log,         :level_nuage)
       apply_config_value(config, $policy_log,        :level_policy)
+      apply_config_value(config, $redfish_log,       :level_redfish)
       apply_config_value(config, $rhevm_log,         :level_rhevm)
       apply_config_value(config, $scvmm_log,         :level_scvmm)
       apply_config_value(config, $vcloud_log,        :level_vcloud)
@@ -121,6 +122,7 @@ def self.create_loggers
       $lenovo_log        = create_multicast_logger(path_dir.join("lenovo.log"))
       $nuage_log         = create_multicast_logger(path_dir.join("nuage.log"))
       $policy_log        = create_multicast_logger(path_dir.join("policy.log"))
+      $redfish_log       = create_multicast_logger(path_dir.join("redfish.log"))
       $rhevm_log         = create_multicast_logger(path_dir.join("rhevm.log"))
       $scvmm_log         = create_multicast_logger(path_dir.join("scvmm.log"))
       $vcloud_log        = create_multicast_logger(path_dir.join("vcloud.log"))