Resolve "Make gitlab run PHPunit tests"

Closes #16

.gitlab-ci.yml

@@ -24,7 +24,8 @@ unit_tests:
   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
+  - apt-get install -y git php-common
+  - apt-get install -y composer
   - composer install
   script:
   - phpunit tests/*.php