Merge branch 'DockerBuildNoCache' into 'master'

do not use cache for building

See merge request ifs/GitlabMarkdownToPDF!17

.gitlab-ci.yml

@@ -15,7 +15,7 @@ BuildPandocImage:
   tags:
   - docker
   script:
-  - docker build --build-arg VCS_REF=$CI_COMMIT_SHA --tag=$PANDOC_IMAGE --file=Dockerfile.pandoc .
+  - docker build --no-cache --build-arg VCS_REF=$CI_COMMIT_SHA --tag=$PANDOC_IMAGE --file=Dockerfile.pandoc .
   - docker login -u gitlab-ci-token -p $CI_JOB_TOKEN $CI_REGISTRY
   - docker push $PANDOC_IMAGE