message: make test world add single track model
diff: @@ -55,7 +55,7 @@ WorldPtr bark::world::tests::make_test_world(
  auto params = std::make_shared<SetterParams>();
  ExecutionModelPtr exec_model(new ExecutionModelInterpolate(params));
  - DynamicModelPtr dyn_model(nullptr);
  + DynamicModelPtr dyn_model(new SingleTrackModel(params));
  BehaviorModelPtr beh_model_idm(new BehaviorIDMClassic(params));
  BehaviorModelPtr beh_model_const(new BehaviorConstantVelocity(params));
  