added drone file

.drone.yml

@@ -0,0 +1,30 @@
+kind: pipeline
+name: default
+
+steps:
+- name: build
+  image: golang
+  commands:
+  - go build
+
+- name: gitea_release
+  image: plugins/gitea-release
+  settings:
+    api_key: 
+      from_secret: GITEA_API_KEY
+    base_url: https://git.kapelle.org
+    files:
+    - sunset
+    checksum:
+    - md5
+    - sha1
+    - sha256
+    title: v0.1
+    prerelease: true
+  when:
+    event: 
+    - tag
+
+trigger:
+  event:
+  - tag