Asset instruction (#5)

* Add asset instruction to load an asset file

Author: Roxeena

runner/testsuite/instruction.py

@@ -28,6 +28,7 @@
 
 Allowed_Types = [
   "action",
+  "asset",
   "deltatime",
   "navigationstate",
   "pause",
@@ -94,6 +95,10 @@ async def run(self, openspace):
         print(f"    Action: {self.value}")
         await openspace.action.triggerAction(self.value)
 
+      case "asset":
+        print(f"    Asset: {self.value}")
+        await openspace.asset.add(self.value)
+
       case "deltatime":
         print(f"    Deltatime: {self.value}")
         await openspace.time.setDeltaTime(self.value)