Make sure we have the zip command when running the tests

.gitlab-ci.yml

@@ -6,6 +6,7 @@ test:
         GIT_COMMITTER_NAME: dummy
         GIT_COMMITTER_EMAIL: dummy@example.org
     script:
+        - apt-get update && apt-get install -y zip
         - if [ ! -e .poetry/bin/poetry ] ; then
         # Poetry is not installed (note: $HOME tells get-poetry.py were to install)
         -   curl -sSL https://raw.githubusercontent.com/python-poetry/poetry/master/get-poetry.py | HOME=$PWD python