Fix #47, one of oldest open bugs (yay!): support @JsonValue for Map keys
diff --git a/release-notes/VERSION b/release-notes/VERSION
index 03644d2..3c8ee7d 100644
--- a/release-notes/VERSION
+++ b/release-notes/VERSION
@@ -6,6 +6,7 @@
 
 2.5.0 (not yet released)
 
+#47: Support `@JsonValue` for (Map) key serialization 
 #113: Problem deserializing polymorphic types with @JsonCreator
 #408: External type id does not allow use of 'visible=true'
 #421: @JsonCreator not used in case of multiple creators with parameter names