How to add a fixed role (e.g. Admin) to an existing Asp.Net Mvc/Identity 2 site?
In the link
http://bitoftech.net/2015/03/11/asp-net-identity-2-1-roles-based-authorization-authentication-asp-net-web-api/, there are the following code which is exactly what I want to do. However, will the Seed function be executed since the application? (I already have some code, var lookup1 = new List<L1>{new L1 {...},...}; tableL1.ForEach(l => context.tableL1.AddOrUpdate(p=>p.Title, l)); context.SaveChanges();, in the Seed function to seed some lookup tables.). What's the right way to Add a role to an application which is already online?  
// internal sealed class Configuration : DbMigrationsConfiguration<ApplicationDbContext>
internal sealed class Configuration : DbMigrationsConfiguration<ApplicationDbContext>
{
    public Configuration()
    {
        AutomaticMigrationsEnabled = false;
    }
    protected override void Seed(AspNetIdentity.WebApi.Infrastructure.ApplicationDbContext context)
    {
        //  This method will be called after migrating to the latest version.
        var manager = new UserManager<ApplicationUser>(new UserStore<ApplicationUser>(new ApplicationDbContext()));
        var roleManager = new RoleManager<IdentityRole>(new RoleStore<IdentityRole>(new ApplicationDbContext()));
        var user = new ApplicationUser()
        {
            UserName = "SuperPowerUser",
            Email = "taiseer.joudeh@gmail.com",
            EmailConfirmed = true,
            FirstName = "Taiseer",
            LastName = "Joudeh",
            Level = 1,
            JoinDate = DateTime.Now.AddYears(-3)
        };
        manager.Create(user, "MySuperP@ss!");
        if (roleManager.Roles.Count() == 0)
        {
            roleManager.Create(new IdentityRole { Name = "SuperAdmin" });
            roleManager.Create(new IdentityRole { Name = "Admin"});
            roleManager.Create(new IdentityRole { Name = "User"});
        }
        var adminUser = manager.FindByName("SuperPowerUser");
        manager.AddToRoles(adminUser.Id, new string[] { "SuperAdmin", "Admin" });
    }
}