Policy invoker function should account an array of middlewares

[XVincentX]

It's a common practice in Express to install an array of middlewares, rather than a single one.

This would be really handy for polices that basically export a set of middlewares.

Currently, the only way to do that is by chaining the functions one by one:

    return urlEncoded(req, res, (err) => {
      if (err) return next(err);
      tokenIntrospection(req.body.token, req.body.token_type)

While the idea would be to do:

return [urlEncoded, (req,res,next)=>{/* my stuff */}]