DAVID LEWIS, EDWARD McALLISTER and SALIOU SAMB IN 2016, Mamady Doumbouya, a commander in the Guinean army, asked his superiors if he could have ammunition to train his troops in marksmanship. He never received it, he said, because they feared he would use the rounds to launch a coup. Five years on, Doumbouya did just that. On Sunday, after hours of gunfire in the capital Conakry, the 41-year-old appeared in an online video in army fatigues and wrap-around sunglasses to declare President Alpha Conde ousted and the government dissolved. "We call on our brothers in arms to unite in order…