public void ConfigureServices(IServiceCollection services)

        {

            services.AddDbContext<ApplicationDbContext>(options =>

                options.UseSqlServer(Configuration.GetConnectionString("DefaultConnection")));

            services.AddIdentity<ApplicationUser, IdentityRole>()

                .AddEntityFrameworkStores<ApplicationDbContext>()

                .AddDefaultTokenProviders();

            services.Configure<IdentityOptions>(options=> {

                options.Password.RequireDigit = true;

                options.Password.RequiredLength = ;

                options.Password.RequireNonAlphanumeric = false;

                options.Password.RequireUppercase = false;

                options.Password.RequireLowercase = false;

            });

            // Add application services.

            services.AddTransient<IEmailSender, EmailSender>();

            services.AddMvc();

        }