Serde deserialization is broken

[A-Manning]

#[test]
fn serialize_lower_roundtrip() -> Result<(), serde_json::Error> {
    let bytes: [u8; 4] = [0xdeu8, 0xad, 0xbe, 0xef];
    let serialized: serde_json::Value =
        hex_conservative::serde::serialize_lower(&bytes, serde_json::value::Serializer)?;
    let deserialized: [u8; 4] = hex_conservative::serde::deserialize(serialized)?;
    assert_eq!(bytes, deserialized);
    Ok(())
}

This panics during deserialization, due to attempting to deserialize as a map here, instead of deserializing as a str.

    if d.is_human_readable() {
        d.deserialize_map(HexVisitor(PhantomData))
    } else {
        serde::Deserialize::deserialize(d)
    }

Fixed in #188

[apoelstra]

NIce find! Looks like a copy/paste error. Originates in #37. Neither reviewer noticed.