message: chain-core: add debug trait.
diff: @@ -244,6 +244,7 @@ pub mod testing {
  /// Pair with a ledger and transaction that is valid in such state.
  /// This structure is used for tests generation, when the framework
  /// require user to pass valid transaction.
  + #[derive(Clone, Debug)]
  pub struct LedgerWithValidTransaction<L, T>(pub L, pub T);
  /// Test that checks if arbitrary valid transaction succeed and can
  