title: Sequelize.js foreign key
body: <p>When using Sequelize.js, the following code doesn't add any foreign key on tables. </p>
  
  <pre><code>var MainDashboard = sequelize.define('main_dashboard', {
    title: Sequelize.STRING
  }, {
    freezeTableName: true
  })
  
  MainClient.hasOne(MainDashboard, { foreignKey: 'idClient' })
  MainDashboard.hasOne(MainClient, { foreignKey: 'clientId' })
  
  sequelize.sync({ force: true })
  </code></pre>
  
  <p>Is there any way to force Sequelize.js to add these foreign key constraints?</p>