Update changelog with 2.0.3 release (#335)

Author: briangustafson

CHANGELOG.md

@@ -3,7 +3,7 @@ All notable changes to this project will be documented in this file.
 
 The format is based on [Keep a Changelog](http://keepachangelog.com/).
 
-## Unreleased
+## 2.0.3 - 2017-10-26
 
 ### Added
 - Filters for most core, IAM, and Load Balancer data sources. See [docs/Filters.md](https://github.com/oracle/terraform-provider-oci/blob/master/docs/Filters.md) for details.