(cloudwatch) update changelog (grafana#5080)

* update cloudwatch.md

* update changelog

Author: mtanda

CHANGELOG.md

@@ -7,6 +7,7 @@
 
 # 3.0.3 Patch release (unreleased)
 * **Time picker**: Fixed issue timepicker and UTC when reading time from URL, fixes [#5078](https://github.com/grafana/grafana/issues/5078)
+* **CloudWatch**: Support for Multiple Account by AssumeRole, closes [#3522](https://github.com/grafana/grafana/issues/3522)
 
 # 3.0.2 Patch release (2016-05-16)
 

docs/sources/datasources/cloudwatch.md

@@ -26,6 +26,8 @@ Name | The data source name, important that this is the same as in Grafana v1.x
 Default | Default data source means that it will be pre-selected for new panels.
 Credentials profile name | Specify the name of the profile to use (if you use `~/aws/credentials` file), leave blank for default. This option was introduced in Grafana 2.5.1
 Default Region | Used in query editor to set region (can be changed on per query basis)
+Custom Metrics namespace | Specify the CloudWatch namespace of Custom metrics
+Assume Role Arn | Specify the ARN of the role to assume
 
 ## Authentication