Celtic’s need for a new goalkeeper was brought into sharp focus for next season the minute Joe Hart announced he was retiring at the end of the season. Joe Hart‘s contract expires at the end of the season and whilst many may have hoped that the popular veteran ‘keeper would have stayed on for another season, the 36-year-old clearly wants to go out on a high. This has led to all sorts of speculation surrounding who could replace the treble-winning hero with Caoimhin Kelleher being one name in the frame. Celtic learned last week that the Liverpool number two could cost them as much as £20-£30m w…