High altitude, low results.  That’s been Colorado Rockies baseball for the last seven seasons and through the first 18 games of this one.  The Rockies struck out 10 times against Houston’s Spencer Arrighetti in Wednesday’s 3-1 loss to extend their six-game slide. They’ll look to avoid getting swept for the second time this season when Juan Mejia (0-2, 5.40 ERA) pays greetings to Houston’s Ryan Weiss (0-2, 7.36 ERA) on Thursday evening. It’s been only a couple of weeks since the Rockies swept