message: add createDoi as a write-only attr on registration model
diff: @@ -56,6 +56,7 @@ export default class RegistrationModel extends NodeModel.extend(Validations) {
  // Write-only attributes
  @attr('array') includedNodeIds?: string[];
  + @attr('boolean') createDoi?: boolean;
  @computed(
  'withdrawn', 'embargoed', 'public', 'pendingRegistrationApproval',
  