text: 
  exports.up = function (knex, Promise) {
    return knex.schema.createTable('users', (table) => {
      table.increments('user_id').primary();
      table.string('username').unique();
      table.string('avatar_url');
      table.string('name');
    });
  };
  
  exports.down = function (knex, Promise) {
    return knex.schema.dropTable('users');
  };
  