Merge pull request #55 from hhu-propra2/serialization-tests

added deserialization tests

src/main/java/mops/gruppen2/domain/event/DeleteUserEvent.java

@@ -11,4 +11,6 @@ public class DeleteUserEvent extends Event {
     public DeleteUserEvent(Long event_id, Long group_id, String user_id) {
         super(event_id, group_id, user_id);
     }
+
+    public DeleteUserEvent() {}
 }

src/main/java/mops/gruppen2/domain/event/Event.java

@@ -8,8 +8,8 @@ import lombok.NoArgsConstructor;
 
 
 @Getter
-@NoArgsConstructor
 @AllArgsConstructor
+@NoArgsConstructor
 @JsonTypeInfo(
         include = JsonTypeInfo.As.PROPERTY,
         use = JsonTypeInfo.Id.NAME,