Upgrade translation of the 6 Chapter to the latest version of the book (Rails 3.2.13, 2nd edition).
Upgrade translation of the 7 Chapter to the latest version of the book (Rails 3.2.13, 2nd edition).
Upgrade translation of the 8 Chapter to the latest version of the book (Rails 3.2.13, 2nd edition).
Upgrade translation of the 9 Chapter to the latest version of the book (Rails 3.2.13, 2nd edition).