Add some component tests to reference unity project (#86)

* Add some component tests to reference unity project

* Use action/setup-node@v2 to avoid problems with build

unity-project-with-correct-tests/Assets/Scripts/SampleComponent.cs

@@ -0,0 +1,17 @@
+using UnityEngine;
+
+public class SampleComponent : MonoBehaviour
+{
+  public BasicCounter Counter;
+
+  void Start()
+  {
+    Counter = new BasicCounter(5);
+  }
+
+  // Update is called once per frame
+  void Update()
+  {
+    Counter.Increment();
+  }
+}