Updated changelog.

See #1127

Author: mp911de

src/main/resources/changelog.txt

@@ -1,6 +1,11 @@
 Spring Data Couchbase Changelog
 ===============================
 
+Changes in version 4.2.1 (2021-05-14)
+-------------------------------------
+* #1136 - upgrade java sdk to 3.1.5.
+
+
 Changes in version 4.1.9 (2021-05-14)
 -------------------------------------
 
@@ -1408,5 +1413,6 @@ Release Notes - Spring Data Couchbase - Version 1.0 M1 - 2013-09-11
 
 
 
+