chore: remove old GitLab CI config

.gitlab-ci.yml

@@ -1,36 +0,0 @@
-image: docker:latest
-
-services:
-  - "docker:dind"
-
-before_script:
-  - "docker login -u \"$CI_REGISTRY_USER\" -p \"$CI_REGISTRY_PASSWORD\" $CI_REGISTRY"
-
-build-master:
-  stage: "build"
-  script:
-    - "docker build --pull -t \"$CI_REGISTRY_IMAGE\" ."
-    - "docker push \"$CI_REGISTRY_IMAGE\""
-  only:
-    - "master"
-
-build:
-  stage: "build"
-  script:
-    - "docker build --pull -t \"$CI_REGISTRY_IMAGE:$CI_COMMIT_REF_SLUG\" ."
-    - "docker push \"$CI_REGISTRY_IMAGE:$CI_COMMIT_REF_SLUG\""
-  except:
-    - "master"
-
-deploy-dockerhub:
-  stage: "deploy"
-  before_script:
-    - "docker login -u \"$DOCKERHUB_USER\" -p \"$DOCKERHUB_PASSWORD\""
-    - "docker login -u \"$CI_REGISTRY_USER\" -p \"$CI_REGISTRY_PASSWORD\" $CI_REGISTRY"
-  script:
-    - "docker pull \"$CI_REGISTRY_IMAGE\""
-    - "docker tag \"$CI_REGISTRY_IMAGE\" \"$DOCKERHUB_USER/$DOCKERHUB_PROJECT\""
-    - "docker push \"$DOCKERHUB_USER/$DOCKERHUB_PROJECT\""
-  only:
-    - "master"
-