Reinstate drupal-check in the-build's own CI testing.

.circleci/config.yml

@@ -46,6 +46,19 @@ jobs:
           name: Configure URL in /etc/hosts
           command: echo 127.0.0.1 ${CIRCLE_PROJECT_REPONAME}.local | sudo tee -a /etc/hosts
 
+      # Note: phing and drupal-check have mutually exclusive requirements.
+      # It'd be better to add drupal-check as a dependency of the drupal project
+      # rather than as part of the virtual environment, but this will have to do
+      # for now. Also note, drupal-check is added as part of the-vagrant so it
+      # is available to run within our VM.
+      - run:
+          name: Install drupal-check
+          command: |
+            curl -O -L https://github.com/mglaman/drupal-check/releases/latest/download/drupal-check.phar
+            mkdir --parents ~/bin
+            mv drupal-check.phar ~/bin/drupal-check
+            chmod +x ~/bin/drupal-check
+
       # Composer package cache
       - restore_cache:
           keys: