Add Gitlab CI config file

6 jobs for master in 13 minutes and 24 seconds (queued for 1 second)
latest
Status Job ID Name Coverage
  Build
passed #197972
build

00:02:30

 
  Test
passed #197975
autopkgtest

00:03:48

passed #197976
blhc

00:01:37

passed #197974
lintian

00:02:21

passed #197977
piuparts

00:04:08

passed #197973
reprotest

00:02:53