Fixed sample plugin

By: Dinnerbone <dinnerbone@dinnerbone.com>

paper-api/sample/src/com/dinnerbone/bukkit/sample/SamplePlugin.java

@@ -34,7 +34,7 @@ public class SamplePlugin extends JavaPlugin {
     }
 
     private void registerEvents() {
-        getServer().getPluginManager().registerEvent(Event.Type.JOIN, playerListener, Priority.Normal, this);
-        getServer().getPluginManager().registerEvent(Event.Type.QUIT, playerListener, Priority.Normal, this);
+        getServer().getPluginManager().registerEvent(Event.Type.PLAYER_JOIN, playerListener, Priority.Normal, this);
+        getServer().getPluginManager().registerEvent(Event.Type.PLAYER_QUIT, playerListener, Priority.Normal, this);
     }
 }