set google analytics tag
add 'optional' notice
update gem file and guard file
通知を1周間より最近なものに限定
Merge pull request #117 from tadyjp/set-ga

[Review] set google analytics tag
Merge pull request #119 from tadyjp/fix-notification

通知機能リファクタ
Merge commit '3eff2d2a8e3cec3250224105467cb92f54176ff8' into set-hipchat

Conflicts:
	config/settings.yml.example