chore: add space

Author: Davide Melfi

aws-lambda-java-tests/RELEASE.CHANGELOG.md

@@ -3,6 +3,7 @@
 - Add serialization round-trip tests covering 66 event classes
 - Bumped `aws-lambda-java-serialization` to version `1.4.0` (Jackson `2.15.x` → `2.18.6`)
 - Bumped `aws-lambda-java-events` to version `3.16.1`
+
 ### August 26, 2021
 `1.1.1`:
 - Bumped `aws-lambda-java-events` to version `3.11.0`