Changed the health decrement for a more proper statement

Zookeepers Trial/Assets/Scripts/PlayerHealth.cs

-using UnityEngine;
+using UnityEngine;
 using System.Collections;
 using UnityEngine.SceneManagement;
 
@@ -21,7 +21,7 @@ public class PlayerHealth : MonoBehaviour {
     void OnTriggerEnter2D(Collider2D other) {
         if (other.gameObject.tag == "Enemy") {
             Debug.Log("hit");
-            health--;
+            health = health - 1;
         }
     }
 
@@ -31,4 +31,4 @@ public class PlayerHealth : MonoBehaviour {
     void OnLevelWasLoaded() {
         spawn.player.transform.position = spawn.spawnPoint[EnterDoor.spawnPointIndex].position;
     }
-}
+}
\ No newline at end of file