Add publish_tagged_rpm and needed helper derived from https://gitlab.cern.ch/ci-tools/ci-web-deployer as we need to run the update_repo.sh hook after the file transfert.

Adding cta_tagged_rpm stage. CTA_RELEASE and CTA_VERSION are not exported as is to avoid overriding environment variables used by cmake. Therefore I am using TAG_VERSION and TAG_RELEASE.

Print CTA_BUILD_ID in the jobs and not the full SHA of the commit of course. The generated rpm version was OK but the logs were useless.

`CI_BUILD_REF` environment variable has been dropped in [gitlab 9.0](https://cern.service-now.com/service-portal/view-outage.do?n=OTG0037271)

now expiring artifacts after 30 days as the repository was reaching 10GB quota limit (by the way this limit has been raised to 20GB today).

Now `run_systemtest.sh` can be used standalone, outside of CI environment.

Adding Valgrind to gitlab CI based on https://gitlab.cern.ch/dss/dss-ci-docker/blob/master/cta/autotest/Dockerfile dockerfile used in jenkins

it looks like yum-builddep is not grabing repo content, so copy repo files first so that yum takes care of this step

is to then rename the image in the registry after it has been pushed. I
am using the pipelineID to identify the image uniquely.

CONTEXTDIR does not allow to retrieve artifacts from directory under it, therefore move Dockerfile location is the answer (officially)