Adds CHANGELOG entry for #213

Author: weierophinney

CHANGELOG.md

@@ -6,7 +6,8 @@ All notable changes to this project will be documented in this file, in reverse
 
 ### Added
 
-- Nothing.
+- [#213](https://github.com/zendframework/zend-mail/pull/213) re-adds support for PHP 5.6 and 7.0; ZF policy is never
+  to bump the major version of a PHP requirement unless the package is bumping major version.
 
 ### Deprecated