pub fn hex2bytes<H>(hex: H) -> Result<Vec<u8>>where H: AsRef<[u8]>,
AsRef<[u8]> to Vec<u8>.
AsRef<[u8]>
Vec<u8>
Return error if:
assert_eq!( array_bytes::hex2bytes("0x4c6f7665204a616e6520466f7265766572"), Ok(b"Love Jane Forever".to_vec()) );