public async Task <IdentityResult> RegisterUserAsync(string userName, string email, string password)
{
var response = new IdentityResult();
AppUser user = new AppUser
{
UserName = userName,
Email = email
};
response = await this._userManager.CreateAsync(user, password);
ApplicationRoleManager.AddUserToRole(this._userManager, user.Id, "User");
return(response);
}