Update HISTORY and version

HISTORY.md

 # Rocksdb Change Log
+## 6.11.5 (7/23/2020)
+### Bug Fixes
+* Memtable lookup should report unrecognized value_type as corruption (#7121).
+
 ## 6.11.4 (7/15/2020)
 ### Bug Fixes
 * Make compaction report InternalKey corruption while iterating over the input.

include/rocksdb/version.h

@@ -6,7 +6,7 @@
 
 #define ROCKSDB_MAJOR 6
 #define ROCKSDB_MINOR 11
-#define ROCKSDB_PATCH 4
+#define ROCKSDB_PATCH 5
 
 // Do not use these. We made the mistake of declaring macros starting with
 // double underscore. Now we have to live with our choice. We'll deprecate these