Added drone CI config

.drone.yml

@@ -0,0 +1,16 @@
+kind: pipeline
+type: kubernetes
+name: default
+steps:
+- name: docker
+  image: plugins/docker
+  settings:
+    repo: porto.interlegis.leg.br/library/powerdns
+    registry: porto.interlegis.leg.br
+    mirror: https://registrycache.interlegis.leg.br
+    pull: if-not-exists
+    auto_tag: true
+    username:
+      from_secret: porto_user
+    password:
+      from_secret: porto_pw

README.md

@@ -1,6 +1,8 @@
 # docker-powerdns
 PowerDNS docker container, based on Debian Buster.
 
+[![Build Status](https://drone.interlegis.leg.br/api/badges/SEIT/docker-powerdns/status.svg)](https://drone.interlegis.leg.br/SEIT/docker-powerdns)
+
 ## Requirements
 
 ### Docker