Facebookログインボタン、discovery prefelenceの機能追加、viewの整理
Merge branch 'master' of https://github.com/yudai-ushiro/six into facebook

Conflicts:
	app/views/about/index.html.erb
	app/views/about/profile.html.erb
	app/views/videos/_video.html.erb
Merge pull request #25 from yudai-ushiro/facebook

Facebook