message: Test ivk in key components
diff: @@ -497,7 +497,11 @@ fn key_components() {
  assert_eq!(&vec, &tv.nk);
  }
  - // TODO: Test fvk.ivk()
  + {
  + let mut vec = Vec::new();
  + fvk.ivk().into_repr().write_le(&mut vec).unwrap();
  + assert_eq!(&vec, &tv.ivk);
  + }
  let diversifier = Diversifier(tv.default_d);
  let addr = fvk.into_payment_address(diversifier, &JUBJUB).unwrap();
  