Add basic CI/CD functionality

This MR adds a basic CD/CD pipeline, which validates the top-level pipeline.cwl workflow with an example input.

.gitlab-ci.yml

@@ -19,8 +19,9 @@ build_ci_runner_image:
   image: docker
   tags:
     - dind
-  script:
+  before_script: 
     - docker login -u $CI_REGISTRY_USER -p $CI_REGISTRY_PASSWORD $CI_REGISTRY
+  script:
     - |
       if docker pull $CI_REGISTRY_IMAGE/ci-build-runner:$CI_COMMIT_REF_SLUG; then
         docker build --cache-from $CI_REGISTRY_IMAGE/ci-build-runner:$CI_COMMIT_REF_SLUG --tag $CI_REGISTRY_IMAGE/ci-build-runner:$CI_COMMIT_REF_SLUG docker/ci-runner