User

• POST: Sign-in (/auth/sign-in)
• POST: Sign-up (/auth/sign-up)

Author

• GET: List (/authors)
• POST: Create (/authors)
• GET: Show (/authors/:id)
• PUT: Update (/authors/:id)
• DELETE: Delete (/authors/:id)\

Book

• GET: List (/books)
• POST: Create (/books)
• GET: Show (/books/:id)
• PUT: Update (/books/:id)
• DELETE: Delete (/books/:id)