Create drupal8 hiera platform, deploy script

[ohthehugemanatee]

Drupal 8 has some different requirements, and a different deploy process. This should be a hiera/yeoman option for platform=drupal8. Off the top of my head:

• Merge in drupal-composer, simlink vendor/bin/drupal and vendor/bin/drush to /usr/local/bin
• Use /vagrant/web as the docroot (we could symlink, but that confuses PHPStorm into thinking there are two resource roots... and probably other IDEs too)
• Solr 5.x (or maybe 4.x, depends on the status of search_api_solr in 8)
• PHP 5.6 (I understand 7.x doesn't have great contrib support, but we should ask @heddn )
• Different varnish vcl
• Gesso version, status, and requirements are all a bit different.
• Different build, install, CI prep process. ("composer install && drush si --profile=mysite") This is mostly taken care of by depending on drupal-composer, but we'll need a drupal8.rb for our capistrano steps.

[heddn]

Based on https://www.drupal.org/node/2607222, PHP 7 is a fine platform to use as a default. I've been using it a while on D8 and haven't run into any notable issues.

[wwhurley]

Why would we be changing the docroot to web?

[ohthehugemanatee]

because that's the docroot for drupal-composer - see their issue on the subject. "web" is the normal web root for Symfony apps, including the Symfony Standard, which is why drupal-composer uses it.

If we want to stick with public, the alternatives are:

• Symlink public to web, and configure phpstorm et al to ignore one of the roots.
• Change the webroot we get from drupal-composer. That requires changes in composer.json (several locations), .gitignore (several locations), and post-install.sh (only DOCROOT variable at top of the script).