private void MigrateCredentials(User user, List<Credential> creds, string password)
        {
            var toRemove = creds.Where(c => 
                !String.Equals(
                    c.Type, 
                    CredentialTypes.Password.Pbkdf2, 
                    StringComparison.OrdinalIgnoreCase))
                .ToList();

            // Remove any non PBKDF2 credentials
            foreach (var cred in toRemove)
            {
                creds.Remove(cred);
                user.Credentials.Remove(cred);
                CredentialRepository.DeleteOnCommit(cred);
            }

            // Now add one if there are no credentials left
            if (creds.Count == 0)
            {
                user.Credentials.Add(CredentialBuilder.CreatePbkdf2Password(password));
            }

            // Save changes, if any (even though we only commit one repo, both will get saved because they just wrap entities context)
            UserRepository.CommitChanges();
        }