ci: add artifacts to debug

.gitlab-ci.yml

@@ -33,6 +33,14 @@ debian:
     - test/simulator-cpp-client.sh
     # Run integration tests (simgrid simulator VS python client)
     - PATH="${PATH}:/usr/local/bin" test/simulator-py-client.sh
+  artifacts:
+    paths:
+      - client-cpp.err
+      - client-cpp.out
+      - client-py.err
+      - client-py.out
+      - simulator.err
+      - simulator.out
 
 nix:
   stage: unique_stage