[gitlab-ci] install ruby-ipaddress

.gitlab-ci.yml

@@ -19,7 +19,7 @@ validate-data:
     - grid5000-docker
    image: debian:stretch
    script:
-    - apt-get update && apt-get -y install ruby rake ruby-hashdiff wget
+    - apt-get update && apt-get -y install ruby rake ruby-hashdiff ruby-ipaddress wget
     - gem install hash_validator
       # Add G5K CA certificate
     - wget --no-check-certificate -q https://www.grid5000.fr/certs/ca.grid5000.fr.crt -O /usr/local/share/ca-certificates/ca.grid5000.fr.crt