Add clean-up stage in CI.

.gitlab-ci.yml

 stages:
-  - everything
+  - clean
+  - run_tests
+
+clean-spack:
+  stage: clean
+  script:
+    - 'rm -rf /scratch/g/gitlab-runner/autoicon-spack || :'
+    - 'rm -rf /scratch/g/gitlab-runner/autoicon-spackcache || :'
+    - 'rm -rf /scratch/g/gitlab-runner/autoicon-spackconfig || :'
+  tags:
+    - slurm.meteo.physik.lmu.de
+
+  rules:
+    - if: '$CLEAN_UP == "true"'
+      when: always
+    - when: never
+
+
 
 real-from-ideal:
-  stage: everything
+  stage: run_tests
   script:
     - ./examples/01_real-from-ideal.sh
   tags:
@@ -18,7 +35,7 @@ real-from-ideal:
     expire_in: 7 days
 
 real-from-ideal-psp:
-  stage: everything
+  stage: run_tests
   script:
     - ./examples/01_real-from-ideal+psp.sh
   tags:
@@ -34,7 +51,7 @@ real-from-ideal-psp:
     expire_in: 7 days
 
 real-from-dwd-ana:
-  stage: everything
+  stage: run_tests
   script:
     - ./examples/02_real-from-dwd-ana.sh
   tags: