text: DROP TABLE IF EXISTS bookshelf;
  
  CREATE TABLE bookshelf(
    id SERIAL PRIMARY KEY,
    author VARCHAR(255),
    title VARCHAR(255),
    isbn VARCHAR(255),
    image VARCHAR(255),
    description TEXT
  );
  
  -- insert into heroku: `heroku pg:psql -f schema.sql --app your-heroku-app-name-here`.
  
  