By Julien Pretot CULOZ, France, July 17 (Reuters) - Chris Froome has been so strong on this year's Tour de France that at times he appears to have been toying with his rivals. "It was just to see who had the legs," Froome, who still leads Dutchman Bauke Mollema by 1:47, told a news conference after a trouble-free day that featured six climbs. The 160-km stage in the Jura mountains, which included some tricky descents, was an opportunity for Froome's rivals for the yellow jersey to launch some attacks. More...