added yaml file for CI

.drone.yml

@@ -0,0 +1,13 @@
+kind: pipeline
+name: build-arm
+
+platform:
+  os: linux
+  arch: arm
+
+steps:
+- name: test
+  image: rust:1.47
+  commands:
+  - cargo build --release --verbose
+  - cargo test --verbose