Thousands of fans make their way to Ashburn each year for training camp, braving long commutes and the summer heat. Nick Wass/APIt was one of those mornings where you know it’s going to be really hot outside. The sun had not yet risen on Saturday, but the rising temperature and heavy humidity were foreboding.And yet the three parking lots outside the Commanders practice facility in Ashburn featured a line of people so long it started to weave ar…