Function sequoia_autocrypt::cert_builder

pub fn cert_builder<'a, V, U>(version: V, userid: Option<U>) -> CertBuilder<'a>where
    V: Into<Option<Autocrypt>>,
    U: Into<UserID>,

Generates a key compliant to Autocrypt.

If no version is given the latest one is used.

The autocrypt specification requires a UserID. However, because it can be useful to add the UserID later, it is permitted to be none.