Twitch is announcing a bunch of updates at TwitchCon Europe, including the ability to host a vertical livestream and an open beta test that lets creators stream at a higher quality.The rollout of vertical streams should make livestreams easier to watch in portrait mode on your phone. Down the line, streamers won’t be forced to pick between vertical or horizontal streams; instead, Twitch will let streamers offer their streams in a dual format.“This allows us to better optimize the viewing experie...