In this demo, it takes almost twice as much to load
all items on a page without HTTP/2 Server Push.

Change-Id: Ie5c9814c4dcf9ff9f21ed215d4eb58d108715f50
Reviewed-on: https://go-review.googlesource.com/38657
Run-TryBot: Jaana Burcu Dogan <jbd@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Tom Bergan <tombergan@google.com>