`req.app` is not a reference to the `slay.App`

[chrisajimenez]

Problem

I am trying to access app.config that is exposed by slay inside of a middleware, but it doesn't exist. Express exposes both req.app and res.app for this purpose.

Example:

// foo-middleware.js
module.exports = foo(req, res, next) {
  // req.app exists
  // req.app.config does not exist
  next();
}

Investigation

This reference is not updated in slay, and does not have a reference to the new app properties that are documented.

req.app and res.app seem to be set on the prototype of express's app as a re-writable property. Happy to open up a PR to change this in slay, unless there is another way to access the slay app instance from inside of a middleware. (to get access to app.config, for example). This should work by setting app.request.app = app (the slay app instead of the express app).

It looks like slay and broadway inherit properties from express, but don't update this app.request.app reference.