Adding environment variables to control execution

modified: ecal/emcal_electrons.sh

ecal/ecal_config.yml

+ecal_1_emcal_electrons:
+  image: eicweb.phy.anl.gov:4567/eic/juggler/juggler:latest
+  tags:
+    - silicon
+  timeout: 12 hours 30 minutes
+  artifacts:
+    expire_in: 20 weeks
+    paths:
+      - results/
+      - sim_output/
+  stage: run
+  script:
+    - bash ecal/emcal_electrons.sh
+