Attempt image autotagging with dry run (no image pushing)

.drone.yml

@@ -2,7 +2,7 @@ kind: pipeline
 name: default
 steps:
 
-  - name: docker
+  - name: docker-tagged-release
     image: plugins/docker
     settings:
       dockerfile: Dockerfile
@@ -12,22 +12,12 @@ steps:
         from_secret: docker_password
       registry: quay.io
       repo: quay.io/natlibfi/annif
-      tags: [latest]
-
-  - name: docker-dev
-    image: plugins/docker
-    settings:
-      dockerfile: Dockerfile-dev
-      username:
-        from_secret: docker_username
-      password:
-        from_secret: docker_password
-      registry: quay.io
-      repo: quay.io/natlibfi/annif
-      tags: [dev]
+      auto_tag: true
+      dry_run: true
 
 trigger:
   branch:
   - master
+  - issue297-set-docker-image-tag-from-git-tag
   event:
   - push