Add basic Gitlab CI for testing the build

This merely tests against the devel package in Fedora, not against the xserver
from git. Should be enough, the driver here doesn't change enough to need the
git builds.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
2 jobs for wip/ci in 59 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Containers Build
passed #496105
container_build

00:00:20

 
  Build
passed #496106
fedora:30@default-build

00:00:39