public async Task<ActionResult> Redigera(Product product)
 {
     if (ModelState.IsValid)
     {
         db.Entry(product).State = EntityState.Modified;
         await db.SaveChangesAsync();
         return RedirectToAction("Index");
     }
     return View(product);
 }
        public async Task<ActionResult> Skapa(Product product)
        {
            if (ModelState.IsValid)
            {
                product.CreatedOn = DateTime.Now;
                db.Products.Add(await product.AssignValuesAsync(db));
                await db.SaveChangesAsync();
                return RedirectToAction("Index");
            }

            return View(product);
        }