adding building docker image

.drone.yml

@@ -9,3 +9,17 @@ steps:
     - apt-get update
     - apt-get install -y make
     - make test
+
+- name: Build image 
+  image: plugins/docker
+  settings:
+    username:
+      from_secret: gitea_username
+    password:
+      from_secret: gitea_password
+    registry:
+      from_secret: gitea_container_registry
+    auto_tag: true
+  when:
+    event:
+    - tag