It’s the best way to officially welcome summer. Credit: Travel + LeisureThe hotter temps have definitely been a strong sign that summer is within reach, but with the season officially kicking off in just a few days, we can finally say without question—summer is here. And to help you refresh your wardrobe and summer travel arsenal, Nordstrom is hosting a long weekend sale with a bunch of markdowns on warm-weather favorites, like sandals, sleevele…