message: check v1 soft derivation
diff: @@ -923,13 +923,24 @@ mod tests {
  }
  #[test]
  - fn xpub_derive_v1() {
  + fn xpub_derive_v1_hardened() {
  let derivation_index = 0x1;
  let seed = Seed::from_bytes([0;32]);
  let prv = XPrv::generate_from_seed(&seed);
  let child_prv = prv.derive(DerivationScheme::V1, derivation_index);
  }
  + #[test]
  + fn xpub_derive_v1_soft() {
  + let derivation_index = 0x10000000;
  + let seed = Seed::from_bytes([0;32]);
  + let prv = XPrv::generate_from_seed(&seed);
  + let xpub = prv.public();
  + let child_prv = prv.derive(DerivationScheme::V1, derivation_index);
  + let child_xpub = xpub.derive(DerivationScheme::V1, derivation_index).unwrap();
  + assert_eq!(child_prv.public(), child_xpub);
  + }
  +
  #[test]
  fn xpub_derive_v2() {
  let derivation_index = 0x10000000;
  