Remove unnucessary `javascript_include_tag`

Something が went wrong してた。
Thanks, @ursm, @hibariya.
Modify filetype
Remove not used css
Remove not used css
Add photos to "FOR ATTENDEES"
Merge remote-tracking branch 'ruby-no-kai/master' into middleman

Conflicts:
	source/2013/for_attendees.html.haml
bundle update