Use file instead of content

Revert this commit when content
becomes available in docker-engine
See https://github.com/compose-spec/compose-spec/pull/429

services/jelu-application.yml

@@ -0,0 +1,5 @@
+jelu:
+  metadataProviders:  
+    - is-enabled: true  
+      apiKey: "${GOOGLE_API_KEY}"
+      name: "google"

services/jelu.yml

@@ -27,9 +27,5 @@ services:
 
 configs:
   jelu_config:
-    content: |
+    file: ./jelu-application.yml
-      jelu:
+
-        metadataProviders:  
-          - is-enabled: true  
-            apiKey: "${GOOGLE_API_KEY}"
-            name: "google"