Update CI nextflow mod to 19.09.0 for Tower integration

.gitlab-ci.yml

@@ -2,7 +2,7 @@ before_script:
   - module load astrocyte
   - module load python/3.6.1-2-anaconda
   - pip install --user pytest-pythonpath==0.7.1 pytest-cov==2.5.1
-  - module load nextflow/19.07.0
+  - module load nextflow/19.09.0
   - mkdir -p test_data/simple1
   - mkdir -p test_data/simple2
   - ln -sfn /project/shared/bicf_workflow_ref/workflow_testdata/cellranger/cellranger_mkfastq/simple1/* test_data/simple1/