Move vendor directory to the project root

Drupal's root composer.json file has been made user editable so that individual projects can specify their own dependencies independent of Drupal core. This allows users to manage Drupal core, modules, themes, PHP Dependencies, etc. from composer.json.

The root composer.json file is entry point for individual project dependencies. Core dependencies are managed in core/composer.json. core/composer.json gets merged on runtime into the root composer.json with the Wikimedia Composer merge plugin.

core/vendor has been moved to vendor.

If you move between beta15 => beta16, the class map will automatically be updated for you.

If you are trying to move from HEAD / -dev to beta16, you will need to perform one of the following if you are using the APCu cache:

1) Restart Apache
2) Add $settings['rebuild_access'] = TRUE; to your settings.php and run /rebuild.php. (remember to switch it back off after)

This also means you must invoke PHPUnit slightly differently:

./vendor/bin/phpunit -c core