Enabled autoredeploy, removed useless volume

- Autoredeploy allow dockercloud to redeploy container when a new image
is pushed on dockerhub. 
- volume /opt/yacy_search_server/DATA is already declared in docker
image and allow persistence of data inside deployed container.

docker/docker-cloud.yml

@@ -3,5 +3,4 @@ yacy:
   ports:
     - '8090:8090'
   restart: on-failure
-  volumes:
-    - /opt/yacy_search_server
+  autoredeploy: true