MIAMI — Immigration authorities have begun releasing some of the Cuban migrants that were detained in South Florida last week, according to officials, activists and relatives of the detainees. The Miami Herald interviewed several of the Cuban migrants while they were at Broward Transitional Center, an Immigration and Customs Enforcement detention center for immigrants in Pompano Beach. Many had entered the United States through the southern border under Donald Trump’s administration, and been in immigration custody for as much as two years and had asylum claims denied. ICE had released them in…