trying to make docker build produce better logs

backend/serverless.yml

@@ -31,6 +31,8 @@ custom:
     useDocker: true
     dockerSsh: true
     fileName: requirements/base.txt
+    dockerBuildCmdExtraArgs:
+      - '--progress=plain'
   customDomain:
     domainName: api.${self:provider.environment.DOMAIN_NAME}
     createRoute53Record: true