DOC: More specific about versions.

.docker/Dockerfile

@@ -35,4 +35,5 @@ RUN rm -r /git/.git \
 RUN cd /git && pip3 install .
 WORKDIR /git/integrationtests
 CMD /wait-for-it.sh caosdb-server:10443 -t 500 -- ./test.sh
+# At least recommonmark 0.6 required.
 RUN pip3 install recommonmark

README_SETUP.md

@@ -38,4 +38,4 @@ Build documentation in `build/` with `make doc`.
 
 - sphinx
 - sphinx-autoapi
-- recommonmark
+- recommonmark >= 0.6.0