Use docker-build CI

.gitlab-ci.yml

@@ -18,4 +18,4 @@ build:
   - ./bin/python ${PREFIX}/bin/sphinx-apidoc --separate -d 2 --output=doc/api ${CI_PROJECT_NAMESPACE}
   - ./bin/python ${PREFIX}/bin/sphinx-build doc sphinx
   tags:
-  - docker
+  - docker-build