add drone file

.drone.yml

@@ -0,0 +1,11 @@
+kind: pipeline
+type: docker
+name: default
+steps:
+  - name: seelf-deploy
+    image: curlimages/curl
+    environment:
+      SEELF_API_KEY:
+        from_secret: seelf_api_key
+    commands:
+      - /bin/sh -c 'curl -i -X POST -H "Content-Type: application/json" -H "Authorization: Bearer $SEELF_API_KEY" -d "{ \"environment\":\"staging\",\"git\":{ \"branch\": \"master\" } }" https://seelf.voixdunet.com/api/v1/apps/2P5woMQ7sPQQMktVRl08wfJL6b5/deployments'