Use a different namespace in the Docker container.

Also bugfix: Patroni should advertise Docker ip as connect address

docker/entrypoint.sh

@@ -83,10 +83,11 @@ cat > /patroni/postgres.yml <<__EOF__
 
 ttl: &ttl 30
 loop_wait: &loop_wait 10
-scope: &scope ${PATRONI_SCOPE}
+scope: &scope '${PATRONI_SCOPE}'
+namespace: 'patroni'
 restapi:
-  listen: 127.0.0.1:8008
-  connect_address: 127.0.0.1:8008
+  listen: 0.0.0.0:8008
+  connect_address: ${DOCKER_IP}:8008
 etcd:
   scope: *scope
   ttl: *ttl