Gitlab ci

Add pytest-workflow tests and enable gitlab-ci integration, including the slurm runner.

.gitlab-ci.yml

@@ -29,7 +29,7 @@ test-sanity:
 test-dry-run:
   <<: *before_script_anchor
   script:
-    - pytest --keep-workflow-wd-on-fail --basetemp ${BASETEMP} --tag dry-run
+    - pytest --keep-workflow-wd-on-fail --tag dry-run
   image: lumc/singularity-snakemake:3.5.2-5.15.0
   tags:
     - docker