message: add support for custom claims namespace
  Add support for custom claims namespace as per Hasura JWT mode
diff: @@ -28,15 +28,20 @@ module.exports = {
  user_roles.push(user.default_role);
  }
  - return jwt.sign({
  - 'https://hasura.io/jwt/claims': {
  + const claims_namespace = ("claims_namespace" in HASURA_GRAPHQL_JWT_SECRET)
  + ? HASURA_GRAPHQL_JWT_SECRET.claims_namespace
  + : 'https://hasura.io/jwt/claims';
  +
  + const claims = {};
  + claims[claims_namespace] = {
  'x-hasura-allowed-roles': user_roles,
  'x-hasura-default-role': user.default_role,
  'x-hasura-user-id': user.id.toString(),
  'x-hasura-is-anonymous': user.is_anonymous.toString(),
  ...custom_claims,
  - },
  - }, HASURA_GRAPHQL_JWT_SECRET.key, {
  + }
  +
  + return jwt.sign(claims, HASURA_GRAPHQL_JWT_SECRET.key, {
  algorithm: HASURA_GRAPHQL_JWT_SECRET.type,
  expiresIn: `${JWT_TOKEN_EXPIRES}m`,
  });
  