Export WriteOptions.

src/lib.rs

@@ -16,7 +16,7 @@ pub use ffi as rocksdb_ffi;
 pub use ffi::{DBCompactionStyle, DBComparator, new_bloom_filter};
 pub use rocksdb::{DB, DBIterator, DBVector, Direction, IteratorMode, Writable,
                   WriteBatch};
-pub use rocksdb_options::{BlockBasedOptions, Options};
+pub use rocksdb_options::{BlockBasedOptions, Options, WriteOptions};
 pub use merge_operator::MergeOperands;
 pub mod rocksdb;
 pub mod ffi;