public static void Initialize(HotelContext context)
        {
            context.Database.EnsureCreated();
            if (!context.Users.Any())
            {
                var users = new User[]
                {
                    new User {
                        Name = "User1", Password = "******", FirstName = "Jan", LastName = "Kowal", Email = "*****@*****.**", Address = "ul. Piastowa 10, Poznań 69-200"
                    },
                    new User {
                        Name = "User2", Password = "******", FirstName = "Paweł", LastName = "Majch", Email = "*****@*****.**", Address = "ul. Akacjowa 12, Warszawa 88-390"
                    },
                    new User {
                        Name = "User3", Password = "******", FirstName = "Piotr", LastName = "Fort", Email = "*****@*****.**", Address = "ul. Lipowa, Opole 90-445"
                    }
                };

                foreach (User u in users)
                {
                    context.Users.Add(u);
                }
                context.SaveChanges();
            }

            if (!context.Rooms.Any())
            {
                var rooms = new Room[]
                {
                    new Room {
                        RoomNumber = 3, Description = "Pokoj 3 osobowy", BedsCount = 3, Location = "Parter", Price = 300, Rate = 4
                    },
                    new Room {
                        RoomNumber = 41, Description = "Pokoj 2 osobowy", BedsCount = 1, Location = "Pierwsze pietro", Price = 230, Rate = 5
                    },
                    new Room {
                        RoomNumber = 62, Description = "Pokoj 5 osobowy", BedsCount = 5, Location = "Drugie pietro", Price = 395, Rate = 3
                    },
                };
                foreach (Room r in rooms)
                {
                    context.Rooms.Add(r);
                }
                context.SaveChanges();
            }

            if (!context.Payments.Any())
            {
                var payments = new Payment[]
                {
                    new Payment {
                        Method = "Przelew", TotalCost = 300
                    },
                    new Payment {
                        Method = "Gotówka", TotalCost = 100
                    },
                };

                foreach (Payment p in payments)
                {
                    context.Payments.Add(p);
                }
                context.SaveChanges();
            }

            if (!context.Reservations.Any())
            {
                var reserv = new Reservation[]
                {
                    new Reservation {
                        UserID = 1, RoomID = 1, DateFrom = new DateTime(2019, 6, 26, 18, 0, 0), DateTo = new DateTime(2019, 6, 29, 12, 0, 0), Confirmed = true
                    },
                    new Reservation {
                        UserID = 3, RoomID = 3, DateFrom = new DateTime(2019, 6, 28, 16, 0, 0), DateTo = new DateTime(2019, 7, 2, 12, 0, 0), Confirmed = true
                    },
                };
                foreach (Reservation res in reserv)
                {
                    context.Reservations.Add(res);
                }
                context.SaveChanges();
            }
        }