Adding a [HttpGet] attribute to enable the Delete album from the store functionality.

This action corresponds to a confirmation page to delete the item.

src/MusicStore/Controllers/StoreManagerController.cs

@@ -117,6 +117,7 @@ namespace MusicStore.Controllers
         //
         // GET: /StoreManager/Delete/5
 
+        [HttpGet]
         public IActionResult Delete(int id = 0)
         {
             Album album = db.Albums.Single(a => a.AlbumId == id);