Add Gitlab CI config file

8 jobs for master in 27 minutes and 21 seconds (queued for 2 seconds)
latest
Status Job ID Name Coverage
  Build
passed #279770
build

00:03:41

 
  Test
passed #279775
autopkgtest

00:03:03

passed #279776
blhc

00:01:36

passed #279774
lintian

00:03:09

passed #279777
piuparts

00:04:23

passed #279773
reprotest

00:04:13

passed #279772
test-build-all

00:03:35

passed #279771
test-build-any

00:03:37