DENVER — The Yankees have insisted that they’re a championship-caliber team all season. But actions speak far louder than words, and the former has made the latter hard to believe when it comes to this team. On Sunday, the Yankees accentuated that point when they lost an 8-7 game — and a series — to the 36-win Rockies, the worst team in the National League. Afterward, Aaron Boone dismissed a…