message: expose a couple of the transaction-builder helpers
diff: @@ -11,10 +11,13 @@ export {
  } from './keys'
  export {
  nextYear, nextMonth, nextHour, makeUUID4, updateQueryStringParameter,
  - isLaterVersion, isSameOriginAbsoluteUrl, hexStringToECPair, ecPairToHexString
  + isLaterVersion, isSameOriginAbsoluteUrl, hexStringToECPair, ecPairToHexString,
  } from './utils'
  -export { transactions, safety } from './operations'
  +export {
  + transactions, safety, TransactionSigner,
  + PubkeyHashSigner, addUTXOsToFund, estimateTXBytes
  +} from './operations'
  export { network } from './network'
  