Enugu tech bros and Nigeria’s yabacon valley, by Osmund Agbo   A friend of mine visited from Nigeria not too long ago. He runs an oil servicing company back home and arrived in Houston with the usual armour of his tribe; a MacBook, headphones, and a half-dozen Slack channels humming with activities. On the second day, his lifeline to his company crashed. We spent hours on the phone with Apple support and then at the gleaming Apple Store, only to be told the repair would cost almost as much as a...