Update .gitlab-ci.yml file

.gitlab-ci.yml

@@ -14,7 +14,7 @@ pytest:
 pages:
   script:
     - apt-get update -qy
-    - apt-get install -y python3-dev python3-pip
+    - apt-get install -y python3-dev python3-pip graphviz graphviz-dev
     - pip install pdoc
     - pip install ".[rl]"
     - pdoc --output-dir public overcooked_simulator !overcooked_simulator.reinforcement_learning --logo https://gitlab.ub.uni-bielefeld.de/uploads/-/system/project/avatar/6780/Cooking-Vector-Illustration-Icon-Graphics-4267218-1-580x435.jpg --docformat google