Tidy up our InventoryListener.

src/main/java/com/gmail/nossr50/runnables/PlayerUpdateInventoryTask.java

@@ -0,0 +1,17 @@
+package com.gmail.nossr50.runnables;
+
+import org.bukkit.entity.Player;
+import org.bukkit.scheduler.BukkitRunnable;
+
+public class PlayerUpdateInventoryTask extends BukkitRunnable {
+    private Player player;
+
+    public PlayerUpdateInventoryTask(Player player) {
+        this.player = player;
+    }
+
+    @Override
+    public void run() {
+        player.updateInventory();
+    }
+}