Update Drone configuration and Dockerfile to use mirrorred images.

Expect pipeline to fail.

.drone.yml

@@ -5,27 +5,27 @@ name: build
 
 steps:
   - name: lint
-    image: golangci/golangci-lint:v1.43.0
+    image: code.pztrn.name/containers/mirror/golangci/golangci-lint:v1.46.2
     environment:
       CGO_ENABLED: 0
     commands:
       - golangci-lint run
 
   - name: test
-    image: golang:1.17.3-alpine
+    image: code.pztrn.name/containers/mirror/golang:1.18.3-alpine
     environment:
       CGO_ENABLED: 0
     commands:
       - go test ./...
 
   - name: docker
-    image: plugins/docker
+    image: code.pztrn.name/containers/mirror/plugins/docker:20.13.0
     when:
       branch: ["master"]
     settings:
-      username:
-        from_secret: dockerhub_user
+      registry: code.pztrn.name
+      username: drone
       password:
-        from_secret: dockerhub_password
-      repo: pztrn/metricator
+        from_secret: drone_secret
+      repo: code.pztrn.name/apps/metricator
       auto_tag: true