Adds bitcask & bitraft to Database section (#2776)

* Adds bitcask & bitraft to Database section

* Update README.md

README.md

@@ -380,6 +380,7 @@ Please take a quick gander at the [contribution guidelines](https://github.com/a
 * [badger](https://github.com/dgraph-io/badger) - Fast key-value store in Go.
 * [bcache](https://github.com/iwanbk/bcache) - Eventually consistent distributed in-memory  cache Go library.
 * [BigCache](https://github.com/allegro/bigcache) - Efficient key/value cache for gigabytes of data.
+* [Bitcask](https://github.com/prologic/bitcask) - Bitcask is an embeddable, persistent and fast key-value (KV) database written in pure Go with predictable read/write performance, low latency and high throughput thanks to the bitcask on-disk layout (LSM+WAL).
 * [bolt](https://github.com/boltdb/bolt) - Low-level key/value database for Go.
 * [buntdb](https://github.com/tidwall/buntdb) - Fast, embeddable, in-memory key/value database for Go with custom indexing and spatial support.
 * [cache](https://github.com/akyoto/cache) - In-memory key:value store with expiration time, 0 dependencies, <100 LoC, 100% coverage.