Update HISTORY.md for Listener

Summary: Update HISTORY.md for Listener

Test Plan: no code change

Reviewers: igor, sdong, IslamAbdelRahman, anthony

Reviewed By: anthony

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D41325

HISTORY.md

@@ -5,6 +5,9 @@
 * Added experimental support for optimistic transactions.  See include/rocksdb/utilities/optimistic_transaction.h for more info.
 * Added a new way to report QPS from db_bench (check out --report_file and --report_interval_seconds)
 * Added a cache for individual rows. See DBOptions::row_cache for more info.
+* Several new features on EventListener (see include/rocksdb/listener.h):
+ - OnCompationCompleted() now returns per-compaciton job statistics, defined in include/rocksdb/compaction_job_stats.h.
+ - Added OnTableFileCreated() and OnTableFileDeleted().
 
 ### Public API changes
 * EventListener::OnFlushCompleted() now passes FlushJobInfo instead of a list of parameters.