message: Add test for spending_key panic on short seed
diff: @@ -30,3 +30,14 @@ pub fn spending_key(seed: &[u8], coin_type: u32, account: u32) -> ExtendedSpendi
  ],
  )
  }
  +
  +#[cfg(test)]
  +mod tests {
  + use super::spending_key;
  +
  + #[test]
  + #[should_panic]
  + fn spending_key_panics_on_short_seed() {
  + let _ = spending_key(&[0; 31][..], 0, 0);
  + }
  +}
  