SEUN SANNI NIGERIA opened a billion-dollar Chinese-built deep seaport in Lagos, which is expected to ease congestion at the country's ports and help it become an African hub for transhipment, handling cargoes in transit for other destinations. President Muhammadu Buhari has made building infrastructure a key pillar of his government's economic policy and hopes that this will help his ruling party win votes during next month's presidential election. The new Lekki Deep Sea Port is 75% owned by the China Harbour Engineering Company and Tolaram group, with the balance shared between the Lagos state government and the Nigerian Ports Authority.…