Fix installing extra requires for rl

.gitlab-ci.yml

@@ -17,6 +17,7 @@ pages:
     - apt-get install -y python3-dev python3-pip
     - pip install pdoc
     - pip install .
+    - pip install .[rl]
     - pdoc --output-dir public overcooked_simulator  --logo https://gitlab.ub.uni-bielefeld.de/uploads/-/system/project/avatar/6780/Cooking-Vector-Illustration-Icon-Graphics-4267218-1-580x435.jpg --docformat google
   artifacts:
     paths: