Running back Duke Johnson is calling it a career after playing in the NFL for eight seasons. Johnson went to Instagram on Sunday to announce his retirement. He was selected by the Cleveland Browns in the third round of the 2015 NFL Draft after having a strong career with the Miami Hurricanes. “8 Years 4 teams with 1 goal in mind, create a better life for my family,” Johnson wrote in the Instagram post. “I never dreamed of being the all time leading rusher of my dream school or being somewhere on the list of all time players to come out of South FL. I just wanted an opportunity to play a game t…