CHANGELOG.md in logstash-output-datadog_metrics-3.0.2 vs CHANGELOG.md in logstash-output-datadog_metrics-3.0.4

@@ -1,4 +1,10 @@
+## 3.0.4
+  - Docs: Set the default_codec doc attribute.
+
+## 3.0.3
+  - Update gemspec summary
+
 ## 3.0.2
   - Fix some documentation issues
 
 ## 3.0.0
   - Update to the new logstash event api