Add ockam to Rust's section (#147)

README.md

@@ -369,6 +369,7 @@ encryption library providing MD5, SHA1, SHA2 hashing and HMAC functionality, as
 
 - [dalek cryptography](https://github.com/dalek-cryptography/) - Fast yet safe mid-level API for ECC, Bulletproofs, and more.
 - [mundane](https://github.com/google/mundane) - is a Rust cryptography library backed by BoringSSL that is difficult to misuse, ergonomic, and performant.
+- [ockam](https://github.com/ockam-network/ockam) - is a Rust library for end-to-end encryption and mutual authentication.
 - [octavo](https://github.com/libOctavo/octavo) - Highly modular & configurable hash & crypto library.
 - [proteus](https://github.com/wireapp/proteus) - Axolotl protocol implementation, without header keys, in Rust.
 - [recrypt](https://github.com/IronCoreLabs/recrypt-rs) - A pure-Rust library that implements cryptographic primitives for building a multi-hop Proxy Re-encryption scheme, known as Transform Encryption.