Hours before they allegedly gunned down Miami rapper XXXTentacion on June 18, 2018, Robert Allen, Michael Boatwright, Trayvon Newsome, and Dedrick Williams planned a mission for that day. “What area are we going to rob people,” was the question, as Allen testified on February 8, his first day on the witness stand as the murder trial of his three former cohorts commenced last week in a Broward County courtroom…