Log Message:
Update to cryptonite-0.28

0.28
* Add hash constant time capability
* Prevent possible overflow during hashing by hashing in 4GB chunks

0.27
* Optimise AES GCM and CCM
* Optimise P256R1 implementation
* Various AES-NI building improvements
* Add better ECDSA support
* Add XSalsa derive
* Implement square roots for ECC binary curve
* Various tests and benchmarks