调整 Books#collection
Add Books::Collection#create
Add Books::Collection#update
Add Books::Collection#delete
调整 Annotation 接口
Add Books::Annotation#create
Add Books::Annotation#update
Add Books::Annotation#delete
Add Books#review
Add Books::Review::create
Add Books::Review#get
Add Books::Revoew#update
Add Books::Review#delete
Rename Books => Book
Autoloader
Delete old files