Remove redundant `/notification` path component

services/notifications/app.coffee

@@ -24,7 +24,7 @@ app.post '/user/:user_id', controller.addNotification
 app.get '/user/:user_id', controller.getUserNotifications
 app.del '/user/:user_id/notification/:notification_id', controller.removeNotificationId
 app.del '/user/:user_id', controller.removeNotificationKey
-app.del '/notification/key/:key', controller.removeNotificationByKeyOnly
+app.del '/key/:key', controller.removeNotificationByKeyOnly
 
 app.get '/status', (req, res)->
 	res.send('notifications sharelatex up')