Merge branch '35-build-test-image' into 'master'

Resolve "Build test image"

Closes #35

See merge request !52
3 jobs for master in 9 minutes and 11 seconds (queued for 5 seconds)
Name Stage Failure
failed
build-test-docker Build
Removing intermediate container 90d89441ad21
---> 9bbee4d3f933
Successfully built 9bbee4d3f933
Successfully tagged source.dodis.ch:4577/metagrid-go/metagrid-vue:49c22e17ec59e5f8205d267ebb750de51e7dbe5f
$ docker push $CI_REGISTRY_IMAGE:latest-test
The push refers to repository [source.dodis.ch:4577/metagrid-go/metagrid-vue]
tag does not exist: source.dodis.ch:4577/metagrid-go/metagrid-vue:latest-test
Cleaning up file based variables
ERROR: Job failed: exit code 1