Fixed bug with saving to flat file.

Must remember to include blank constructor so Beans can create the
object!

src/main/java/bskyblock/addon/challenges/database/object/ChallengeLevels.java

@@ -16,6 +16,7 @@ import us.tastybento.bskyblock.database.objects.DataObject;
  */
 public class ChallengeLevels implements DataObject, Comparable<ChallengeLevels> {
 
+    public ChallengeLevels() {}
 
     @ConfigComment("A friendly name for the level. If blank, level name is used.")
     private String friendlyName = "";

src/main/java/bskyblock/addon/challenges/database/object/Challenges.java

@@ -22,6 +22,8 @@ import us.tastybento.bskyblock.database.objects.DataObject;
  *
  */
 public class Challenges implements DataObject {
+    
+    public Challenges() {}
 
     public enum ChallengeType {
         /**

src/main/java/bskyblock/addon/challenges/database/object/PlayerData.java

@@ -21,7 +21,7 @@ import us.tastybento.bskyblock.util.Util;
  *
  */
 public class PlayerData implements DataObject {
-
+    
     @Expose
     private String uniqueId = "";
     /**