Disable CI vio2vo job for now

.gitlab-ci.yml

@@ -50,6 +50,7 @@ vio2vo:
     cat build-log-vio2vo.txt  | egrep "[a-zA-Z0-9_/-]+ \(user: [0-9]" | tee build-time-vio2vo.txt
   only:
   - master
+  allow_failure: true
   artifacts:
     paths:
     - coq/ra/build-time-vio2vo.txt