Update python testing versions

.gitlab-ci.yml

 before_script:
-  - module add  python/3.6.1-2-anaconda
-  - pip install --user pytest-pythonpath==0.7.1 pytest-cov==2.5.1
+  - module add  python/3.6.4-anaconda
+  - pip install --user pytest==6.2.2 pytest-pythonpath==0.7.3 pytest-cov==2.11.1
   - module load nextflow/20.01.0
   - ln -s /project/shared/bicf_workflow_ref/workflow_testdata/chipseq/*fastq.gz test_data/