Republican presidential hopeful and billionaire real-estate mogul Donald Trump sent a scathing letter to Univision’s CEO Friday, banning the network’s staff from his Miami golf resort. “Please be advised that under no circumstances is any officer or representative of Univision allowed to use Trump National Doral, Miami — its golf courses or any of its facilities,” Trump wrote to CEO and President Randy Falco. “Also, please immediately stop work and close the gate which is being constructed between our respective properties,” Trump added. “If this is not done within one week, we will close it.” The billionaire, known for his...