Drone: only rollout image on tag/promotion

.drone.yml

@@ -13,6 +13,10 @@ services:
     privileged: true
     environment:
       DOCKER_TLS_CERTDIR: ""
+    when:
+      event:
+        - tag
+        - promote
 
 steps:
   - name: node.js build
@@ -33,9 +37,17 @@ steps:
       DOCKER_HOST: tcp://localhost:2375
       DOCKER_REGISTRY:
         from_secret: DOCKER_REGISTRY
+    when:
+      event:
+        - tag
+        - promote
 
   - name: k8s rollout
     image: bitnami/kubectl
     commands:
       - cd deploy && kubectl apply -f .
       - kubectl rollout -n mathy restart deployment/mathy
+    when:
+      event:
+        - tag
+        - promote