Add .gitlab-ci.yml

.gitlab-ci.yml

+# Select image from https://hub.docker.com/_/php
+image: php:5.6
+
+before_script:
+# Install dependencies
+- bash ci/docker_install.sh > /dev/null
+
+test:app:
+  script:
+  - phpunit --configuration phpunit_myapp.xml
\ No newline at end of file