add drone deploy

.drone.yml

@@ -0,0 +1,21 @@
+---
+kind: pipeline
+type: ssh
+name: deploy
+server:
+    host:
+        from_secret: host
+    user:
+        from_secret: username
+    ssh_key:
+        from_secret: ssh_key
+clone:
+    disable: true
+trigger:
+    branch:
+        - master
+steps:
+    - name: deploy
+      commands:
+          - sudo -Hu www-data git -C /var/www/rfc.tildeverse.org pull --rebase origin master
+