change: Switched the state controller and scene controller to a singleton class

This doesnt' change any of the logic, but simplifies a lot of the main
game loop code.

Many things still rely on the singleton class, but shouldn't so this
will be fixed in a later commit

Assets/Scripts/VictoryObjectBehavior.cs

@@ -8,7 +8,8 @@ public class VictoryObjectBehavior : MonoBehaviour
     public float speed = 1f;
     Vector2 initPosition;
 
-    void Awake() {
+    void Awake()
+    {
         initPosition = this.transform.position;
     }
 
@@ -18,13 +19,16 @@ public class VictoryObjectBehavior : MonoBehaviour
         transform.position = new Vector2(initPosition.x, initPosition.y + Mathf.Sin(Time.time * speed) * height);
     }
 
-    void OnDrawGizmos() {
+    void OnDrawGizmos()
+    {
         Gizmos.DrawLine(new Vector3(transform.position.x, transform.position.y - height, transform.position.z), new Vector3(transform.position.x, transform.position.y + height, transform.position.z));
     }
 
-    void OnTriggerEnter2D(Collider2D col) {
-        if (col.tag == "Player") {
-            GameObject.FindGameObjectWithTag("StateController").GetComponent<StateController>().ShowVictoryCanvas();
+    void OnTriggerEnter2D(Collider2D col)
+    {
+        if (col.tag == "Player")
+        {
+            StateController.Instance.ShowVictoryCanvas();
         }
     }
 }