Add the userTags field to the Item.java (minio#1540)

Author: DonHoe

api/src/main/java/io/minio/messages/Item.java

@@ -57,6 +57,9 @@ public abstract class Item {
   @Element(name = "UserMetadata", required = false)
   private Metadata userMetadata;
 
+  @Element(name = "UserTags", required = false)
+  private String userTags;
+
   private boolean isDir = false;
   private String encodingType = null;
 
@@ -111,6 +114,10 @@ public Map<String, String> userMetadata() {
     return (userMetadata == null) ? null : userMetadata.get();
   }
 
+  public String userTags() {
+    return userTags;
+  }
+
   /** Returns whether this version ID is latest. */
   public boolean isLatest() {
     return isLatest;