Added automatic linting container builds.

.gitlab-ci.yml

@@ -3,6 +3,7 @@ variables:
 
 
 stages:
+  - docker-build
   - lint_build_test
   - deploy
 
@@ -65,3 +66,25 @@ firebase-deploy:
     - firebase deploy --only hosting
   only:
     - production
+docker-build:
+  stage: docker-build
+  image:
+    name: docker/compose:1.24.1
+    entrypoint:
+      - /bin/sh
+      - "-c"
+  services:
+    - docker:dind
+  variables:
+    DOCKER_HOST: "tcp://docker:2375/"
+    DOCKER_DRIVER: overlay2
+    GIT_SUBMODULE_STRATEGY: none
+  only:
+    changes:
+      - docker-compose.yml
+      - linting/**/*
+  before_script:
+    - echo $CI_JOB_TOKEN | docker login -u gitlab-ci-token --password-stdin $CI_REGISTRY
+  script:
+    - docker-compose build
+    - docker-compose push