Add graphviz

.gitlab-ci.yml

@@ -16,7 +16,7 @@ publish-docs:
   stage: deploy
   before_script:
     - apt-get update
-    - apt-get install doxygen -y
+    - apt-get install doxygen graphviz -y
     - 'which ssh-agent || ( apt-get update -y && apt-get install openssh-client -y )'
     - eval $(ssh-agent -s)
     - echo "$DOCS_SSH_PRIVATE_KEY" | tr -d '\r' | ssh-add - > /dev/null