[noise] Test vector format

[Alex]

On Sun, 10 Apr 2016 20:33:15 -0700
Trevor Perrin <trevp at trevp.net> wrote:

> Yeah, that sounds fine: so if "fail: true" you omit the "payload" from
> the message object, and processing the ciphertext is expected to
> produce an error.
> 

Yes. There are a few edge cases though:

 - What happens if "fail" is set to false and a payload is omitted?

 - What happens if decryption succeeds despite "fail: true" and the
   payload being omitted?

-- 
Alex