add a full_title helper
update home page
add bootstrap-sass to gemfile
use bootstrap-sass ver.2.1
add custom css to use bootstrap
update custom css. add universal style
update h1 of home page
update custom css. add typography
update custom css. add logo style.
move html to partial
add footer partial
add footer style to css
refactor css. use mixin
remove default root page
add path of static pages to route
update link path on header and footer
update rspec test. refactor test code