Update .gitlab-ci.yml

.gitlab-ci.yml

 before_script:
-  - module add  python/3.6.1-2-anaconda
+  - module add  python/3.6.4-anaconda
   - pip install --user pytest-pythonpath==0.7.1 pytest-cov==2.5.1
   - module load singularity/3.0.2
   - module load nextflow/19.09.0