Resolve "Make gitlab run PHPunit tests"

Closes #16

.gitlab-ci.yml

@@ -22,6 +22,7 @@ unit_tests:
   stage: "unit_tests"
   image: "php:7.4"
   before_script:
+  - docker-php-ext-install php-common php-composer-ca-bundle  php-composer-semver  php-composer-spdx-licenses php-composer-xdebug-handler php-json-schema php-psr-log php-symfony-console
   - apt-get update -yqq
   - apt-get install -y git composer
   - composer install