A week after closing its deal to acquire Time Warner, AT&T unveiled a new video service called WatchTV that seeks to capture the millions of consumers who’ve severed the pay TV cord — or never subscribed in the first place. The skinny bundle of programming will be available for as little as $15 a month, and offered free to AT&T customers with certain unlimited data plans. WatchTV will offer a bundle of some 30 television channels, including newly acquired CNN, TNT and…