add drone build

.drone.yml

@@ -0,0 +1,48 @@
+kind: pipeline
+type: docker
+name: default
+
+steps:
+- name: make
+  image: docker:dind
+  environment:
+    USERNAME:
+      from_secret: docker_username
+    PASSWORD:
+      from_secret: docker_password
+    REGISTRY:
+      from_secret: docker_registry
+  volumes:
+  - name: dockersock
+    path: /var/run
+  commands:
+  - sleep 5 # give docker enough time to start
+  - docker login -u $USERNAME -p $PASSWORD $REGISTRY
+  - make manifest-list
+- name: notify
+  image: plugins/matrix
+  when:
+    status:
+    - success
+    - failure
+  settings:
+    homeserver:
+      from_secret: matrix-homeserver
+    roomid:
+      from_secret: matrix-room-id
+    userid:
+      from_secret: matrix-user-id
+    accesstoken:
+      from_secret: matrix-access-token
+
+services:
+- name: docker
+  image: docker:dind
+  privileged: true
+  volumes:
+  - name: dockersock
+    path: /var/run
+
+volumes:
+- name: dockersock
+  temp: {}

Makefile

@@ -38,7 +38,9 @@ SHELL := sh
 SRC_DIRS := cmd pkg # directories which hold app source (not vendored)
 
 # Windows not working atm
-ALL_PLATFORMS := linux/amd64 linux/arm linux/arm64 linux/ppc64le linux/s390x
+#ALL_PLATFORMS := linux/amd64 linux/arm linux/arm64 linux/ppc64le linux/s390x
+# Unlikely I'll run on ppc or s390x anytime soon
+ALL_PLATFORMS := linux/amd64 linux/arm linux/arm64
 
 # Used internally.  Users should pass GOOS and/or GOARCH.
 # hacked this to at least guess if go isn't installed on the host