add drone config

.drone.yml

@@ -0,0 +1,26 @@
+---
+kind: pipeline
+name: test and build image
+steps:
+  - name: test code
+    image: golang:1-alpine
+    command:
+      - apk add --no-cache build-base make
+      - make test
+    when:
+      event:
+        include:
+          - push
+  - name: test and build image
+    image: plugins/docker
+    settins:
+      purge: true
+      registry: docker.mtfos.xyz
+      repo: docker.mtfos.xyz/mtfos/tcp-proxy
+      autotag: true
+      tags:
+        - "${DRONE_COMMIT}"
+        - "${DRONE_TAG}"
+    when:
+      ref:
+        - refs/tags/**