Running athena in CI

• Remove anything not associated to the changes in the CI (it seems like only .gitlab-ci.yml should stay) [in new branch slc6-atlasos]
• Probably the correct execution relies on cvmfs being mounted in the gitlab runner. Check whether we need to use runners with cvmfs tag https://gitlab.cern.ch/atlas-physics/pmg/mcjoboptions/-/settings/ci_cd (we do)
• Check if we need to use atlas_external_cvmfs image or if it's enough to use tags:cvmfs (in fact we don't need these, by default cvmfs tagged runners do the jobs)
• Check whether we need to do anything specific for GRID files that live on eos. Do we need the eos image to run the job? (Here we need to add: before_script: - echo ${K8S_SECRET_SERVICE_PASSWORD} | kinit ${SERVICE_ACCOUNT}@CERN.CH, eos image is not needed)
• Build docker image from atlas_external_cvmfs and gitlab-registry.cern.ch/atlas-physics/pmg/mcjoboptions:eos_bash (this is not needed now)
• Check whether slc6 or cc7 is used (most probably it's the former but good to check - then #33 (closed) can be closed) (Runners use: CentOS Linux release 7.6.1810 (Core), so if slc6 is needed then we may use image:atlas_external_cvmfs or image: atlas/slc6-atlasos)
• Use this new image to test with (new image not needed)
  • 421001 (simple jO)(tested with Runners/image: atlas/slc6-atlasos)
  • 421003 (contains GRID file)(tested with Runners/image: atlas/slc6-atlasos)
  • Make sure that the final solution for merging also solves #52 (closed) (checked with above two jobs with Runners/image: atlas/slc6-atlasos, no such problem exist!)