message: fix(hbar): add missing validateKeySignatures method
diff: @@ -202,7 +202,7 @@ export class Hbar extends BaseCoin {
  return co<Buffer>(function* cosignMessage() {
  const msg = Buffer.isBuffer(message) ? message.toString('utf8') : message;
  // reconstitute keys and sign
  - return new bitgoAccountLib.Hbar.KeyPair({ prv: key.prv }).signMessage(msg);
  + return Buffer.from(new bitgoAccountLib.Hbar.KeyPair({ prv: key.prv }).signMessage(msg)).toString('hex');
  })
  .call(this)
  .asCallback(callback);
  