Pipeline: variation on pages build

.gitlab-ci.yml

@@ -80,7 +80,7 @@ unit-test-job:   # This job runs in the test stage.
 pages-job:
   stage: pages
   script:
-  - pip install -U sphinx
+  - pip install -U sphinx m2r2
   - pip install -e .
 #  - cd docs
  # - .\make html