Update .gitlab-ci.yml

1 job for master in 1 minute and 24 seconds (queued for 3 seconds)
latest
Status Job ID Name Coverage
  Test
failed #4012
docker
test

00:01:24

 
Name Stage Failure
failed
test Test
Using docker image sha256:437508e0f491dcc00e395574b73d3a07e4cd8d240f405f24bc012b8234291f47 for php:7.1-apache ...
Running on runner-8cfdb2b6-project-35-concurrent-0 via runner02.ffnw.de...
Cloning repository...
Cloning into '/builds/netmon-sc/api-server'...
Checking out 918b1bd7 as master...
Skipping Git submodules setup
$ composer install --prefer-dist
/bin/bash: line 51: composer: command not found
ERROR: Job failed: exit code 1