- Catch bad config errors.

Rename DefaultsConfig to ActiveConfig, and move the code determining the YML file path into it so we can load it later statically.

- Create a "Provision" base class.
- Load in our existing Application so our existing commands are still available.
- Add a provision-robo.php executable file and change the include in bin/provision.

Adding our own ConsoleOutput.php class with methods for ->erase() to remove lines from console, and ->exec() to run a command and display a spinning output indicator.

Issue #2912579: Move provision from drush: First Steps: composer.json, bin/provision, src/Application.php. It runs!