Add Drone CI

.drone.yml

@@ -0,0 +1,19 @@
+---
+kind: pipeline
+name: deploy to swarm-test.autonomic.zone
+steps:
+  - name: deployment
+    image: decentral1se/stack-ssh-deploy:latest
+    settings:
+      host: swarm-test.autonomic.zone
+      stack: postfix-relay
+      purge: true
+      deploy_key:
+        from_secret: drone_ssh_swarm_test
+    environment:
+      DOMAIN: swarm-test.autonomic.zone
+      STACK_NAME: postfix-relay
+      LETS_ENCRYPT_ENV: production
+trigger:
+  branch:
+    - main