[fix] ci: dump folder must be cleaned and created

.gitlab-ci.yml

@@ -73,6 +73,7 @@ test:
     - yarn test
     # Clean the dump directory before testing
     - rm -rf /tmp/duniter_ci_dump/
+    - mkdir -p /tmp/duniter_ci_dump/
     - bash .gitlab/test/check_indexes.sh /tmp/duniter_ci_dump/
     # Code coverage
     - cp -R coverage /tmp/coverage