chore: Add drone CI configuration.

.drone.yml

@@ -0,0 +1,31 @@
+kind: pipeline
+type: docker
+name: default
+
+steps:
+  - name: build
+    image: docker:dind
+    volumes:
+    - name: dockersock
+      path: /var/run
+    environment:
+      REGISTRY_TOKEN:
+        from_secret: REGISTRY_TOKEN
+    commands:
+    - sleep 5
+    - echo $REGISTRY_TOKEN | docker login code.harton.nz -u james --password-stdin
+    - docker build -t asdf_container --cache-from=code.harton.nz/james/asdf_container:latest .
+    - docker tag asdf_container code.harton.nz/james/asdf_container:latest
+    - docker push code.harton.nz/james/asdf_container:latest
+
+services:
+  - name: docker
+    image: docker:dind
+    privileged: true
+    volumes:
+    - name: dockersock
+      path: /var/run
+
+volumes:
+- name: dockersock
+  temp: {}