Do not install development gems

.gitlab-ci.yml

@@ -20,7 +20,7 @@ validate-data:
    script:
     - apt-get update && apt-get -y install ruby ruby-dev build-essential rake wget
     - gem install bundler -v 1.17.3
-    - bundle install
+    - bundle install --without development
       # Add G5K CA certificate
     - wget --no-check-certificate -q https://www.grid5000.fr/certs/ca2019.grid5000.fr.crt -O /usr/local/share/ca-certificates/ca2019.grid5000.fr.crt
     - /usr/sbin/update-ca-certificates
@@ -35,7 +35,7 @@ generate-reference-api:
    script:
     - apt-get update && apt-get -y install ruby ruby-dev build-essential rake git
     - gem install bundler -v 1.17.3
-    - bundle install
+    - bundle install --without development
     - export TZ=Europe/Paris
     - rake reference-api
     - git status