added drone support

.drone.yml

@@ -0,0 +1,34 @@
+platform: linux/arm
+
+workspace:
+   base: /home/builder/package
+   path: /
+   
+clone:
+  default:
+    image: plugins/git:linux-arm
+    depth: 50
+
+pipeline:
+  build:
+    image: arm32v6/abuild:latest
+    environment:
+      - REPODEST=/home/builder/package
+    secrets:
+      - source: abuild_ssh_key
+        target: RSA_PRIVATE_KEY
+      - source: abuild_ssh_key_name
+        target: RSA_PRIVATE_KEY_NAME
+
+  gitea_release:
+    image: plugins/gitea-release:linux-arm
+    files: builder/armhf/*.apk
+    checksum:
+      - md5
+      - sha1
+      - sha256
+      - sha512
+    secrets: [ gitea_token ]
+    base_url: https://git.asperti.com
+    when:
+      event: tag