Add Drone CI config

.drone.yml

@@ -0,0 +1,17 @@
+kind: pipeline
+type: docker
+name: default
+
+steps:
+  - name: build
+    image: rust
+    environment:
+      SECRET_INPUT:
+        from_secret: secret_input
+    commands:
+      - cargo build --verbose --all
+      - cargo test --verbose --all
+      # Simple test
+      - 'echo "Input: $SECRET_INPUT"'
+      - cargo run $SECRET_INPUT > output
+      - 'echo "Output: " && cat output'