allow loading of external config file

[armandopadilla]

The change allows users to load an external autoreload config. If non is provided the default one is used. Essentially, gives the user more control of this pack's underlining behavior without having to touch the npm-module directly.

How to use

1. Create new file within your trails app. config/autoreload.js
2. Add content

module.exports = {
cwd: '/srv/project',
ignoreInitial: true,
usePolling: true
}

1. Reload app.

[scott-wyatt]

+1 for this functionality. Are you able to write a test for this as well? Also, please follow the eslint guidelines so that this passes the PR CI tests.

[armandopadilla]

will do and on it!

[disciple-dev]

Need to remove semicolons on lines 39 & 42 for CI tests to pass.

[scott-wyatt]

This functionality might be solved by trailsjs/trails#236 or trailsjs/trailpack#39