Add ClearLog support for the Redfish Event Log Service

This change adds support for the LogService.ClearLog action to
clear the Redfish Event Log.

Tested:
   1. Added entries to the EventLog
   2. Sent the ClearLog action using Postman:
      /redfish/v1/Systems/system/LogServices/EventLog/Actions/LogService.ClearLog
   3. Confirmed that the EventLog was empty
   4. Added entries to the EventLog
   5. Confirmed that the new entries logged successfully

Change-Id: I6ac4ea4aff8d7defbea693a2c8a755a712fb39a6
Signed-off-by: Jason M. Bills <jason.m.bills@linux.intel.com>
diff --git a/redfish-core/include/redfish.hpp b/redfish-core/include/redfish.hpp
index 6237e47..91578f1 100644
--- a/redfish-core/include/redfish.hpp
+++ b/redfish-core/include/redfish.hpp
@@ -76,6 +76,7 @@
 
         nodes.emplace_back(std::make_unique<SystemLogServiceCollection>(app));
         nodes.emplace_back(std::make_unique<EventLogService>(app));
+        nodes.emplace_back(std::make_unique<EventLogClear>(app));
         nodes.emplace_back(std::make_unique<EventLogEntryCollection>(app));
         nodes.emplace_back(std::make_unique<EventLogEntry>(app));