add edit to books controller
add update and it's spec
be able to click image_tag
modify edit result spec
modify let and id:
modify let and id:
use context update book
modify let!
remove "#{}"
replace to specify from it
modify conflict
replace let! features/books_spec.rb
use subject
more concrete describe description
add spec when book cannot save
modify book update spec and change to "update_attributes" from "update_cloumns"
Merge pull request #6 from cosmo0920/editing-books

Editing books