Add drone CI config.

.drone.yml

@@ -0,0 +1,11 @@
+kind: pipeline
+name: build-and-test
+
+steps:
+- name: test
+  image: rust:1.47
+  commands:
+  - apt-get update
+  - apt-get install -y cmake
+  - cargo build --verbose --all
+  - cargo test --verbose --all