message: update out tests of the old Diff based API
diff: @@ -123,7 +123,7 @@ pub trait HasHeader {
  }
  /// Trait identifying the message identifier type.
  -pub trait MessageId: Eq + Hash + Clone + Debug {}
  +pub trait MessageId: Eq + Hash + Clone + Debug + Serialize + Deserialize {}
  /// A message is some item contained in a block, such as a
  /// transaction, a delegation-related certificate, an update proposal,
  @@ -340,6 +340,7 @@ pub mod testing {
  TestResult::from_bool(decoded_t == t)
  }
  + /*
  /// test that arbitrary generated transaction fails, this test requires
  /// that all the objects inside the transaction are arbitrary generated.
  /// There is a very small probability of the event that all the objects
  @@ -424,7 +425,7 @@ pub mod testing {
  let id2 = tx2.id();
  (id1 == id2 && tx1 == tx2) || (id1 != id2 && tx1 != tx2)
  }
  -
  + */
  /// Checks the associativity
  /// i.e.
  ///
  