PORT JERVIS — Justin Ropke was a lance corporal in the United States Marine Corps, a scout sniper when he was deployed to Afghanistan.He also was diagnosed with cancer when he was 15 years old. Despite that, Justin had the perfect life, according to his mother, Lisa Ropke, who told Justin’s story at a forum hosted by the Times Herald-Record at Port Jervis High School on Wednesday evening.Justin enlisted after his father died.