Swith to nose2

.gitlab-ci.yml

@@ -9,9 +9,9 @@ coverage:
   script:
   - conda create -n treex -y python=3
   - source activate treex
-  - conda install networkx numpy matplotlib scikit-learn nose coverage
+  - conda install networkx numpy matplotlib scikit-learn nose2 coverage
   - python -m pip install -e .
-  - MPLBACKEND=Agg nosetests -v
+  - MPLBACKEND=Agg nose2 -v
   only:
   - master