Add influxdb dependency

This patch adds the influxdb library as dependency the gitlab runner
which will allow the mangement of influxdb setups using the new
monitoring module from the infrastructure repository.[1]

[1]: 9ae68023f1/roles/monitoring

Dockerfile

@@ -10,6 +10,6 @@ RUN true \
     && apt-get update \
     && apt-get install -y software-properties-common \
     && apt-add-repository --yes --update ppa:ansible/ansible \
-    && apt-get install -y ansible \
+    && apt-get install -y ansible python3-influxdb \
     && apt-get clean && apt-get purge && rm -r /var/lib/apt/lists/* \
     && true