Updated changelog.

See #3561

src/main/resources/changelog.txt

@@ -1,6 +1,18 @@
 Spring Data MongoDB Changelog
 =============================
 
+Changes in version 3.1.6 (2021-03-17)
+-------------------------------------
+* #3592 - Remove @Persistent from entity-scan include filters.
+* #3590 - Embedded sharding keys are not correctly picked up from the shardKeySource Document.
+* #3589 - Upgrade to MongoDB Driver 4.1.2.
+* #3573 - Json Schema section appears twice in reference documentation.
+* #3568 - MongoSocketWriteException may be translated into DataAccessResourceFailureException.
+* #3566 - Couldn't find PersistentEntity for type java.lang.Object when updating a field with suffix "class".
+* #3552 - UpdateMapper drops numeric keys in Maps.
+* #3395 - Derived findBy…IgnoreCaseIn query doesn't return expected results [DATAMONGO-2540].
+
+
 Changes in version 3.0.8.RELEASE (2021-03-17)
 ---------------------------------------------
 * #3590 - Embedded sharding keys are not correctly picked up from the shardKeySource Document.
@@ -3354,5 +3366,6 @@ Repository
 
 
 
+