title: Node.js sequelize model file don't take into account configuration
body: <p>I have the model file which looks as follows:</p>
  
  <pre><code>'use strict'
  
  module.exports = function (sequelize, DataTypes) {
    let User = sequelize.define('user', {
      id: {
        type: DataTypes.INTEGER(11),
        allowNull: false,
        primaryKey: true,
        autoIncrement: true
      }
    }, {
      classMethods: {
        associate: function(models) {
          this.belongsToMany(models.role, {
            through: {
              model: 'user_role'
            },
            foreignKey: 'user_id'
          })
        }
      }
    }, {
      tableName: 'user',
      timestamps: false,
      underscored: true
    }
  )
  return User
  }
  </code></pre>
  
  <p>When I try to make any query on this model I get an error, <code>SequelizeDatabaseError: Table 'sc.users' doesn't exist</code>. It is true that database <code>users</code> doesn't exist, its name is <code>user</code>. I added information about it in my model (<code>tableName: 'user'</code>). </p>
  
  <p>I don't understand why sequelize don't read my configuration options.
  How should I prepare my model file in order to sqeuelize could read configurations from it?</p>