SELIM BORA has had quite a run. In March his company, Summa, won a contract to rebuild and run Guinea Bissau’s new international airport. Months earlier it had completed a 50,000-seat national stadium in Senegal, after less than 18 months of work—a sprint-like pace for such projects. The company’s résumé also includes convention centres in the Democratic Republic of Congo and Equatorial Guinea, a sports arena in Rwanda, and airports…