add support for gitlab-ci

* .gitlab-ci.yml: here.
1 job for er/gitlab-ci in 3 minutes and 9 seconds (queued for 2 minutes and 26 seconds)
Status Job ID Name Coverage
  Test
failed #1538
debian-stable-gcc

00:03:09

 
Name Stage Failure
failed
debian-stable-gcc Test
doc/local.am:22: installing 'build-aux/mdate-sh'
Makefile.am:25: 'doc/local.am' included from here
doc/local.am:22: installing 'build-aux/texinfo.tex'
Makefile.am:25: 'doc/local.am' included from here
parallel-tests: installing 'build-aux/test-driver'
autoreconf: Leaving directory `.'
$ make -k
make: *** No targets specified and no makefile found. Stop.
ERROR: Job failed: exit code 1