Enable CS2 grid builder in test

Author: mo-jonasganderton

src/tests/grid/test_cubedsphere_2.cc

@@ -36,8 +36,7 @@ CASE("cubed_sphere_instantiation") {
 
 CASE("constructor_with_grid") {
     auto grid_og = Grid("O32");
-    // auto grid_cs = Grid("CS-LFR-4-2"); // The grid factory is implemented in the next PR
-    auto grid_cs = CubedSphereGrid2(4);
+    auto grid_cs = Grid("CS-LFR-4-2");
     EXPECT( CubedSphereGrid2( grid_og ).valid() == false );
     EXPECT( bool(CubedSphereGrid2( grid_og )) == false );
     EXPECT( CubedSphereGrid2( grid_cs ).valid() == true );