Fix heap memory issue

src/main/java/d4dj/d4dj/App.java

@@ -215,6 +215,7 @@ public class App
 						drawData(g,leaderboard5, 20, (i+105)*26, 130, (i+105)*26+24, cropPoints3[i].x+351, cropPoints3[i].y+34, cropPoints3[i].x+481, cropPoints3[i].y+58, null);
 					}
 					ImageIO.write(cropped1,"png",new File("testing_leaderboardnames.png"));
+					g.dispose();
 				} catch (Exception e) {
 					System.out.println(e.getMessage());
 				}