use sub client proxyBackBeatApis client for cloudserver client following bump to 1.0.4

Issue: S3UTILS-221

Author: SylvainSenechal

Clients/CloudserverClient.js

@@ -69,21 +69,21 @@ class Client {
 
     getLocationsStatus(callback) {
         const command = new GetLocationsStatusCommand({});
-        this.client.send(command)
+        this.client.proxyBackbeatApis.send(command)
             .then(data => callback(null, data))
             .catch(err => callback(err));
     }
 
     listFailed(params, callback) {
         const command = new ListFailedCommand(params);
-        this.client.send(command)
+        this.client.proxyBackbeatApis.send(command)
             .then(data => callback(null, data))
             .catch(err => callback(err));
     }
 
     retryFailedObjects(params, callback) {
         const command = new RetryFailedObjectsCommand(params);
-        this.client.send(command)
+        this.client.proxyBackbeatApis.send(command)
             .then(data => callback(null, data))
             .catch(err => callback(err));
     }