add #648 to CHANGELOG.md

Author: bsideup

CHANGELOG.md

@@ -9,6 +9,8 @@ All notable changes to this project will be documented in this file.
 
 ## [1.7.2] - 2018-04-30
 
+- Add support for private repositories using docker credential stores/helpers (fixes [\#567](https://github.com/testcontainers/testcontainers-java/issues/567))
+
 ### Fixed
 - Add support for private repositories using docker credential stores/helpers (fixes [\#567](https://github.com/testcontainers/testcontainers-java/issues/567))
 - Retry any exceptions (not just `DockerClientException`) on image pull ([\#662](https://github.com/testcontainers/testcontainers-java/issues/662))