The browser cache doesn't refresh after an app update

[Argn0]

for netlify and main url

[howardchung]

Might have to do with the PWA @albertcui

[albertcui]

So I kind of fixed this in 683fe70.

The service worker generated by CRA is default cache first, so the current behavior is the best we can do: page loads then user gets a prompt to update the page.

Once facebook/create-react-app#5369 is merged we can change this to online first.