BATON ROUGE - The man convicted of dumping the body of a Georgia contractor who came to Baton Rouge and fatally overdosed was sentenced to nearly two decades in prison Monday. Derrick Perkins, a man who law enforcement said is a known drug dealer and goes by "Stanka," was sentenced to 18 years for obstruction of justice and three years for unlawful disposal of remains. His sentences will run concurrent to one another and he will receive credit f…