Adding Dlang to the list

Summary: Closes https://github.com/facebook/rocksdb/pull/1877

Differential Revision: D4576056

Pulled By: IslamAbdelRahman

fbshipit-source-id: 0f19275

LANGUAGE-BINDINGS.md

@@ -10,3 +10,4 @@ This is the list of all known third-party language bindings for RocksDB. If some
 * PHP - https://github.com/Photonios/rocksdb-php
 * C# - https://github.com/warrenfalk/rocksdb-sharp
 * Rust - https://github.com/spacejam/rust-rocksdb
+* D programming language - https://github.com/b1naryth1ef/rocksdb