delete old micropost and book models
crawler.rb with Mechanize
update crawler and add crawler task
add book model and crawler task
update Book view using scaffold
close #18
close #13
update task crawler
display 10 books per page
add BookCategory model
add task: category-crawler, and update task: crawler to crawl by categories
add user model with password
add sign up
[x] sign up 2h
sign out 0.5h
Merge branch 'feature/Auth' into develop
add basic bootstrap
remove tmp folder
basic layout for books
Merge branch 'feature/layout' into develop