var FacebookAuthenticatonOptions = new FacebookOptions
            {
                AppId = Configuration["Authentication:Facebook:AppId"],
                AppSecret = Configuration["Authentication:Facebook:AppSecret"],
                Events = new OAuthEvents
                {
                    OnCreatingTicket = context =>
                    {
                        var client = new FacebookClient(context.AccessToken);
                        dynamic info = client.Get("me", new { fields = "name,id,email,picture.width(300).height(300)" });
                        context.Identity.AddClaim(new Claim("pictureUrl", (string)info["picture"]["data"]["url"]));
                        context.Identity.AddClaim(new Claim(ClaimTypes.Email, info.email));
                        return Task.FromResult(0);
                    }
                }
            };
            FacebookAuthenticatonOptions.Scope.Add("public_profile");
            FacebookAuthenticatonOptions.Scope.Add("email");
            app.UseFacebookAuthentication(FacebookAuthenticatonOptions);