update release notes

Author: cowtowncoder

release-notes/CREDITS

@@ -51,3 +51,8 @@ Ken Southerland (crowmagnumb@github):
 Peter Royal (osi@github)
   * Reported #50: `Instant` schema representation is incorrect for timestamps serialization
    (2.6.4)
+
+Krešimir Nesek (knes1@github)
+  * Reported, contributed for #69: Serialization of Instant seems to throw exceptions
+    when @JsonFormat is used
+   (2.6.6)

release-notes/VERSION

@@ -8,6 +8,8 @@ Project: jackson-datatype-jsr310
 #16: Instant is serialized as String by some dataformats/libs but can't be
   deserialized (unless manually converted to float)
  (reported by Andreas L)
+#69: Serialization of Instant seems to throw exceptions when when @JsonFormat is used
+ (reported and fixed by Krešimir N)
 
 2.6.5 (19-Jan-2016)