0.7.0

Changelog:

• Added FinalizationCryptoError which means cshake and hmac now return a Result on finalization and update function calls.

• Added the ChaCha20 algorithm from the RCF 8439.

• Fix failed builds for no_std.

• Fix a bug where a user could call update() after finalization on both cshake and hmac.

• cshake_verify() function dropped from default API.

• Documentation improvement.