Update CHANGELOG.md
Update CHANGELOG
ADDITIONS
-- Add const values for BatchHeader ServiceClassCode and BatchControl ServiceClassCode. (See [#391](https://github.com/moov-io/ach/issues/391))
-- Add const values for TransactionCode (See [#363](https://github.com/moov-io/ach/issues/363))
+- Add const values for `BatchHeader.StandardEntryClassCode` (See [#392](https://github.com/moov-io/ach/issues/391))
+- Add const values for `BatchHeader.ServiceClassCode` and `BatchControl.ServiceClassCode`. (See [#391](https://github.com/moov-io/ach/issues/391))
+- Add const values for `EntryDetail.TransactionCode` (See [#363](https://github.com/moov-io/ach/issues/363))
## v0.5.0 (Released 2018-11-29)
