adds .gitlab-ci.yml

1 job for master in 13 seconds (queued for 1 second)
Status Job ID Name Coverage
  Test
failed #10282
doxygen
pages

00:00:13

 
Name Stage Failure
failed
pages Test
$ apk add make
(1/1) Installing make (4.2.1-r0)
Executing busybox-1.25.1-r0.trigger
OK: 159 MiB in 57 packages
$ apk add perl
(1/1) Installing perl (5.24.3-r1)
ERROR: perl-5.24.3-r1: package mentioned in index not found (try 'apk update')
1 errors; 159 MiB in 57 packages
ERROR: Job failed: exit code 1