Triplesec v4 Support

[heronhaye]

Hi,
We've released version 4 of Triplesec, detailed at https://keybase.io/triplesec. Only differences are dropping the Twofish phase and switching from Keccak to the SHA3 standard. If you like, you can add support for encrypting and decrypting v4 ciphertexts to your library. Let me know if you have any questions about the spec.

[SamProtas]

Thanks for the heads up. I'll take a look.