Best Coast's Bethany Cosentino took to Twitter today to announce that she's designing an upcoming line for Urban Outfitters. Proof: Stoked to announce my first ever clothing line! Bethany Cosentino for @urbanoutfitters! Drops in May! twitter.com/bestycoastyy/s…— BEST COAST (@bestycoastyy) March 1, 2012 Before people get carried away, realize that there's plenty of precedent for this: Kim Gordon did a line ...