Using OauthAthentication claim are not saved with rc1

[mathieukempe]

I have added the sample code from https://github.com/aspnet/Security/blob/dev/samples/SocialSample/Startup.cs

The context.Identity.AddClaim doesn't add the claim to the document, after saving, the Claims array is empty

Also an error

 app.UseOAuthAuthentication(new OAuthOptions
            {
                AuthenticationScheme = "GitHub",
                DisplayName = "Github",
                ClientId = "",
                ClientSecret = "",
                CallbackPath = new PathString("/signin-github"),
                AuthorizationEndpoint = "https://github.com/login/oauth/authorize",
                TokenEndpoint = "https://github.com/login/oauth/access_token",
                UserInformationEndpoint = "https://api.github.com/user",
                ClaimsIssuer = "OAuth2-Github",
                // Retrieving user information is unique to each provider.
                Events = new OAuthEvents
                {
                    OnCreatingTicket = async context =>
                    {
                        // Get the GitHub user
                        var request = new HttpRequestMessage(HttpMethod.Get, context.Options.UserInformationEndpoint);
                        request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", context.AccessToken);
                        request.Headers.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));

                        var response = await context.Backchannel.SendAsync(request, context.HttpContext.RequestAborted);
                        response.EnsureSuccessStatusCode();

                        var str = await response.Content.ReadAsStringAsync();

                        var user = JObject.Parse(str);

                        var identifier = user.Value<string>("id");
                        if (!string.IsNullOrEmpty(identifier))
                        {
                            context.Identity.AddClaim(new Claim(
                                ClaimTypes.NameIdentifier, identifier,
                                ClaimValueTypes.String, context.Options.ClaimsIssuer));
                        }

                        var userName = user.Value<string>("login");
                        if (!string.IsNullOrEmpty(userName))
                        {
                            context.Identity.AddClaim(new Claim(
                                ClaimsIdentity.DefaultNameClaimType, userName,
                                ClaimValueTypes.String, context.Options.ClaimsIssuer));
                        }

                        var name = user.Value<string>("name");
                        if (!string.IsNullOrEmpty(name))
                        {
                            context.Identity.AddClaim(new Claim(
                                "urn:github:name", name,
                                ClaimValueTypes.String, context.Options.ClaimsIssuer));
                        }

                        var link = user.Value<string>("url");
                        if (!string.IsNullOrEmpty(link))
                        {
                            context.Identity.AddClaim(new Claim(
                                "urn:github:url", link,
                                ClaimValueTypes.String, context.Options.ClaimsIssuer));
                        }
                    }
                }
            });