Added TODO for ds3 client factory per code review.

Author: Hans-Peter Klett

src/main/java/com/spectralogic/ds3client/helpers/Ds3ClientFactoryImpl.java

@@ -24,6 +24,7 @@ public Ds3ClientFactoryImpl(final Ds3Client client) {
         this.client = client;
     }
 
+    //TODO: need to actually return a client that points to a particular server id.
     @Override
     public Ds3Client GetClientForServerId(final String serverId) {
         return this.client;