Automatically refresh an empty notification page on new notifications #530

1. Empty: https://github.com/notifications

   <img width="275" alt="no notif" src="https://user-images.githubusercontent.com/1402241/27506095-c35b0a70-58e3-11e7-91c5-f5dfd886ba81.png">

2. New notification comes

   <img width="275" alt="yes notif" src="https://user-images.githubusercontent.com/1402241/27506096-c55cf388-58e3-11e7-8f1b-c5c754e306b2.png">

3. GitHub don't care

4. Refined GitHub cares and reloads the page

   <img width="275" alt="yes rgh" src="https://user-images.githubusercontent.com/1402241/27506109-0dce81ea-58e4-11e7-89bd-f1918cf995fd.png">

One concern

It's easy to do this when the first notification comes in because the indicator appears in the dom, but I'm not sure if we can know if any further notifications are there without repeating API calls.

If anyone picks this up, they should probably keep this in mind.