CI: Install rdflib earlier to ensure neurdflib goes later

Author: effigies

docker/generate_dockerfiles.sh

@@ -93,7 +93,7 @@ function generate_main_dockerfile() {
     --miniconda create_env=neuro \
                 conda_install='python=${PYTHON_VERSION_MAJOR}.${PYTHON_VERSION_MINOR}
                                libxml2 libxslt matplotlib mkl "numpy!=1.16.0" paramiko
-                               pandas psutil scikit-learn scipy traits' \
+                               pandas psutil scikit-learn scipy traits rdflib' \
                 pip_install="pytest-xdist niflow-nipype1-workflows" \
                 activate=true \
     --copy docker/files/run_builddocs.sh docker/files/run_examples.sh \