ci: Add CI pipeline file

.drone.yml

@@ -0,0 +1,15 @@
+kind: pipeline
+type: docker
+name: default
+
+steps:
+  - name: publish
+    image: rust:slim
+    commands:
+      - /usr/bin/env cargo publish
+    environment:
+      CARGO_REGISTRY_TOKEN:
+        from_secret: cargo_token
+trigger:
+  event:
+    - tag