Add .drone config

.drone.yml

@@ -0,0 +1,23 @@
+pipeline:
+  build:
+    image: ruby
+    commands:
+      - gem install bundler
+      - bundle install
+      - bundle exec jekyll build
+  
+  docker:
+    image: plugins/docker
+    repo: docker.data.coop/cryptohagen-website
+    registry: docker.data.coop
+    secrets: [DOCKER_USERNAME, DOCKER_PASSWORD]
+    username:
+      from_secret: DOCKER_USERNAME
+    password:
+      from_secret: DOCKER_PASSWORD
+    tag: 
+      - "${DRONE_BUILD_NUMBER}"
+      - "latest"
+    when:
+      branch:
+        - master