Update CHANGELOG for Badger2.0.2 release

CHANGELOG.md

@@ -4,6 +4,25 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Serialization Versioning](VERSIONING.md).
 
+## [Unreleased]  
+
+### Fixed
+
+- Cast sz to uint32 to fix compilation on 32 bit. (#1175)
+- Fix checkOverlap in compaction. (#1166)
+- Avoid sync in inmemory mode. (#1190)
+- Improve write stalling on level 0 and 1.
+- Support disabling the cache completely. (#1185)
+- Add support for caching bloomfilters. (#1204)
+- Fix int overflow for 32bit. (#1216)
+- Remove the 'this entry should've caught' log from value.go. (#1170)
+- Rework concurrency semantics of valueLog.maxFid.  (#1187)
+
+### Performance
+
+- Use fastRand instead of locked-rand in skiplist. (#1173)
+- Disable compression and set ZSTD Compression Level to 1. (#1191)
+
 ## [2.0.1] - 2020-01-02 
 
 ### New APIs
@@ -274,7 +293,7 @@ Bug fix:
 ## [1.0.1] - 2017-11-06
 * Fix an uint16 overflow when resizing key slice
 
-[Unreleased]: https://github.com/dgraph-io/badger/compare/v2.0.1...HEAD
+[Unreleased]: https://github.com/dgraph-io/badger/compare/v2.0.2...HEAD
 [2.0.1]: https://github.com/dgraph-io/badger/compare/v2.0.0...v2.0.1
 [2.0.0]: https://github.com/dgraph-io/badger/compare/v1.6.0...v2.0.0
 [1.6.0]: https://github.com/dgraph-io/badger/compare/v1.5.5...v1.6.0