CI: add test (#26)

Reviewed-on: https://codeberg.org/woodpecker-plugins/plugin-docker-buildx/pulls/26
Reviewed-by: anbraten <anbraten@noreply.codeberg.org>
Co-authored-by: 6543 <6543@obermui.de>
Co-committed-by: 6543 <6543@obermui.de>

.woodpecker.yml

@@ -0,0 +1,39 @@
+branches: main
+
+variables:
+    - &platforms 'linux/amd64,linux/arm64'
+    - &golang 'golang:1.18'
+
+pipeline:
+  vendor:
+    image: *golang
+    commands: go mod vendor
+
+  test:
+    image: *golang
+    commands: go test -cover ./...
+
+  publish-dryrun:
+    image: woodpeckerci/plugin-docker-buildx:v20.10.18
+    settings:
+      platforms: *platforms
+      repo: woodpeckerci/plugin-docker-buildx
+      dockerfile: Dockerfile.multiarch
+      dry_run: true
+    when:
+      event: pull_request
+
+  publish:
+    image: woodpeckerci/plugin-docker-buildx:v20.10.18
+    settings:
+      platforms: *platforms
+      repo: woodpeckerci/plugin-docker-buildx
+      auto_tag: true
+      dockerfile: Dockerfile.multiarch
+      username:
+        from_secret: docker_username
+      password:
+        from_secret: docker_password
+    when:
+      event: [push, tag, cron]
+      branch: main