Add default Rust pipeline for drone

.drone.yml

@@ -0,0 +1,10 @@
+# https://readme.drone.io/pipeline/docker/examples/languages/rust/
+kind: pipeline
+name: default
+
+steps:
+- name: test
+  image: rust:1.30
+  commands:
+  - cargo build --verbose --all
+  - cargo test --verbose --all