Issue #2860834: First draft GitLab CI package building and testing

Merge from feature/gitlab-testing up untl b96c03964b8ff7ccddccc6c5a0333d0db07d0e5a
3 jobs for 7.x-3.x in 7 minutes and 40 seconds (queued for 9 minutes and 59 seconds)
latest
Status Job ID Name Coverage
  Build
passed #832
build:deb

00:01:57

 
  Test
passed #833
test:debian-jessie-aegir3-apt

00:03:00

passed #834
test:ubuntu-xenial-aegir3-apt

00:02:42