support drone

.drone.yml

@@ -0,0 +1,24 @@
+kind: pipeline
+type: docker
+name: default
+
+steps:
+- name: build
+  image: maven
+  volumes:
+    - name: cache
+      path: /root/.m2
+  commands:
+    - mvn clean install -DskipTests
+
+trigger:
+  branch:
+    - master
+  event:
+    - pull_request
+    - push
+
+volumes:
+  - name: cache
+    host:
+      path: /root/.m2