drone: switch to new hugo plugin

.drone.yml

@@ -1,18 +1,22 @@
 pipeline:
   build-draft:
-    image: alpine
-    commands:
-      - wget https://github.com/gohugoio/hugo/releases/download/v0.52/hugo_0.52_Linux-64bit.tar.gz -q -O - | tar -xz
-      - ./hugo -D -E -F --theme geeklab
+    image: plugins/hugo
+    hugoVersion: 0.52
+    validate: true
+    buildDrafts: true
+    buildExpired: true
+    buildFuture: true
+    theme: geeklab
     when:
       branch: draft
       event: push
 
   build-prod:
-    image: alpine
-    commands:
-      - wget https://github.com/gohugoio/hugo/releases/download/v0.52/hugo_0.52_Linux-64bit.tar.gz -q -O - | tar -xz
-      - ./hugo -F --theme geeklab
+    image: plugins/hugo
+    hugoVersion: 0.52
+    validate: true
+    buildFuture: true
+    theme: geeklab
     when:
       branch: master
       event: push