Ange Postecoglou has hailed Celtic as an “unbelievable club” after watching his former side win the Scottish Premiership title for a third successive season. The Tottenham Hotspur boss has been under heavy scrutiny down in England over the last week following a series of poor results and his comments in the wake of defeat to Manchester City about ‘fragile foundations’ at the club. [BBC] However, he found some time to switch off and watch the outstanding football on display from Celtic against Kilmarnock on Wednesday night as the Bhoys thumped five goals in to secure three-in-a-row. Several Pos…