0.8.1

This release increases the performance of both parsing and serialization.

There are also some minor fixes to how UTF8 is handled, particularly unexpected unicode characters are now properly reported:

#[test]
fn error_unexpected_unicode_character() {
    let err = parse("\n\nnul🦄\n").unwrap_err();

    assert_eq!(err, JsonError::UnexpectedCharacter {
        ch: '🦄',
        line: 3,
        column: 4,
    });

    assert_eq!(format!("{}", err), "Unexpected character: 🦄 at (3:4)");
}