Support feature worker declaration from gitlab.teklia.com

Closes #1883 (closed)

• Requires tests

arkindex/system_workers.yml

@@ -12,11 +12,17 @@ features:
     s3_ingest:
         image: registry.gitlab.teklia.com/arkindex/workers/import/s3:0.2.0-rc2
     pdf_export:
-        image: registry.gitlab.teklia.com/arkindex/workers/export:0.2.1-rc1
-        command: worker-export-pdf
+        teklia_worker:
+            name: arkindex/workers/export
+            version: 0.2.1-rc1
+            slug: pdf-export
     pagexml_export:
-        image: registry.gitlab.teklia.com/arkindex/workers/export:0.2.1-rc1
-        command: worker-export-pagexml
+        teklia_worker:
+            name: arkindex/workers/export
+            version: 0.2.1-rc1
+            slug: pagexml-export
     docx_export:
-        image: registry.gitlab.teklia.com/arkindex/workers/export:0.2.1-rc1
-        command: worker-export-docx
+        teklia_worker:
+            name: arkindex/workers/export
+            version: 0.2.1-rc1
+            slug: docx-export