text: 
  exports.up = function (knex, Promise) {
    return knex.schema.createTable('topics', (table) => {
      table.string('slug').unique().primary();
      table.string('description').notNullable();
    });
  };
  
  exports.down = function (knex, Promise) {
    return knex.schema.dropTable('topics');
  };
  