Migrations.sol

// Copyright (c) 2016-2017 Clearmatics Technologies Ltd
// SPDX-License-Identifier: LGPL-3.0+
pragma solidity ^0.5.12;

contract Migrations {
  address public owner;
  uint256 public last_completed_migration;

  modifier restricted() {
    if (msg.sender == owner) _;
  }

  constructor() public {
    owner = msg.sender;
  }

  function setCompleted(uint256 completed) public restricted {
    last_completed_migration = completed;
  }

  function upgrade(address new_address) public restricted {
    Migrations upgraded = Migrations(new_address);
    upgraded.setCompleted(last_completed_migration);
  }
}