moved some classes for simplification

src/de/miaurizius/jgame2d/core/UI.java

@@ -1,5 +1,7 @@
 package de.miaurizius.jgame2d.core;
 
+import de.miaurizius.jgame2d.core.enums.GameState;
+
 import java.awt.*;
 
 public class UI {
@@ -20,10 +22,10 @@ public class UI {
         graphics2d.setColor(Color.white);
 
         switch (panel.gameState) {
-            case PLAY:
+            case GameState.PLAY:
 
                 break;
-            case PAUSE:
+            case GameState.PAUSE:
                 drawPauseScreen();
                 break;
         }