Update .gitlab-ci.yml

1 job for master in 17 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Test
failed #155
buildtest

00:00:17

 
Name Stage Failure
failed
buildtest Test There is an unknown failure, please try again
HEAD is now at edeea7c added multimedia repos to ci
From https://git.fsmpi.rwth-aachen.de/videoaginfra/ffworker
edeea7c..b092828 master -> origin/master
Checking out b0928288 as master...
Skipping Git submodules setup
$ echo "deb http://www.deb-multimedia.org stretch main non-free" >> /etc/apt/sources.list
$ curl https://www.deb-multimedia.org/pool/main/d/deb-multimedia-keyring/deb-multimedia-keyring_2016.8.1_all.deb -o deb-multimedia-keyring_2016.8.1_all.deb
/bin/bash: line 53: curl: command not found
ERROR: Job failed: exit code 1