text: 
  /**
   * Run the migrations, adding a integer column called type to the guilds table.
   *
   * @param  {Knex} knex  The Knex database instance
   * @return {Promise}
   */
  exports.up = function (knex, Promise) {
      return knex.schema.table(app.constants.GUILD_TABLE_NAME, table => {
          table.dateTime('leftguild_at')
               .nullable()
               .default(null);
      });
  };
  
  /**
   * Reverse the migrations.
   *
   * @param  {Knex} knex  The Knex database instance
   * @return {Promise}
   */
  exports.down = function (knex, Promise) {
      return knex.schema.table(app.constants.GUILD_TABLE_NAME, table => {
          table.dropColumn('leftguild_at');
      });
  };
  