text: -- +migrate Up
  CREATE TABLE users
  (
  id INTEGER UNSIGNED NOT NULL AUTO_INCREMENT,
  username VARCHAR(255) NOT NULL,
  password VARCHAR(255) NOT NULL,
  created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
  updated_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  
  PRIMARY KEY (id),
  UNIQUE KEY users_username_unique (username)
  ) DEFAULT CHARACTER SET utf8, DEFAULT COLLATE utf8_unicode_ci;
  
  -- +migrate Down
  DROP TABLE users;
  
  