Note: I validated this was working by temporarily changing the URI to
`https://echo.free.beeceptor.com`, which echoes the headers back, then
called `OwlsValueGuide.load_itemdata` directly.
Poking at the site, I didn't love that clicking any of the NC items on
the homepage took a few seconds to load cuz of the OWLS request taking
a couple seconds.
If the request were faster to load I might decide otherwise, but for
now, let's just keep that cache long.
Another approach we could take would be to ask for an endpoint that
returns all the values at once, so we could cache and update them all
together, instead of having it all split into separate cache keys!
