fix: remove 'lib/' in all require statement.
Merge branch 'master' into pamyusoku

Conflicts:
	app/controllers/independent_parts_controller.rb
	app/controllers/root_controller.rb
	app/helpers/application_helper.rb
	lib/meta_info.rb
fix: remove 'lib/' string from all require statement.
bug-fix: helper's link_tags_for method: not joined bug fix.
Merge branch 'master' into pamyusoku
bug-fix: helper method link_tags_for result must be array but it ret string.
Merge branch 'master' into pamyusoku
bug-fix: index's link_tags_for not joined by array and rendering bug fixed.
rm: public/robots.txt for secret.
fix: for sitemap_generator.