Update auto deployment workflow to include rm stack and system prune (#95)

Author: alanna-zhou

.github/workflows/deploy.yml

@@ -35,4 +35,9 @@ jobs:
                   script: |
                       export IMAGE_TAG=${{ steps.vars.outputs.sha_short }}
                       cd docker-compose
+                      docker stack rm the-stack
+                      sleep 20s
+                      sudo systemctl stop nginx
+                      sudo systemctl restart nginx
                       docker stack deploy -c docker-compose.yml the-stack
+                      yes | docker system prune -a