message: [pdsl_model] Add license header to file where it was missing
diff: +// Copyright 2018-2019 Parity Technologies (UK) Ltd.
  +// This file is part of pDSL.
  +//
  +// pDSL is free software: you can redistribute it and/or modify
  +// it under the terms of the GNU General Public License as published by
  +// the Free Software Foundation, either version 3 of the License, or
  +// (at your option) any later version.
  +//
  +// pDSL is distributed in the hope that it will be useful,
  +// but WITHOUT ANY WARRANTY; without even the implied warranty of
  +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  +// GNU General Public License for more details.
  +//
  +// You should have received a copy of the GNU General Public License
  +// along with pDSL. If not, see <http://www.gnu.org/licenses/>.
  +
  mod incrementer;
  