title: How to use Postgres' BIGSERIAL in Sequelize?
body: <p>I would like to use PostgreSQL BIG SERIAL type as an id in Sequelize Model. How do I do this?
  I found that Sequelize uses SERIAL when you do this:</p>
  
  <pre><code>id: {
    type: Sequelize.INTEGER,
    primaryKey: true,
    autoIncrement: true // this converts INT to SERIAL for Postgres
  },
  </code></pre>
  
  <p>But how to make it BIGSERIAL?</p>