docs(CHANGELOG.md): add release 2.2.15 notes

CHANGELOG.md

@@ -4,6 +4,10 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [unreleased] Unreleased
 
+## [2.2.15] 2019-06-28;
+### Fixed
+- call `Codeception\Test\Unit` setup methods in `WPTestCase` to provide Codeception Unit testing facilities in "WordPress unit" test cases
+
 ## [2.2.14] 2019-06-14;
 ### Fixed
 - remove left-over `%WP_URL%` from generated configuration files when runnin `codecept init wpbrowser` and replace it with `%TEST_SITE_WP_URL%` (thanks @HendrikRoehm)
@@ -906,7 +910,8 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 ### Fixed
 - Reference to ModuleConfigException class in WPLoader class.
 
-[unreleased]: https://github.com/lucatume/wp-browser/compare/2.2.14...HEAD
+[unreleased]: https://github.com/lucatume/wp-browser/compare/2.2.15...HEAD
+[2.2.15]: https://github.com/lucatume/wp-browser/compare/2.2.14...2.2.15
 [2.2.14]: https://github.com/lucatume/wp-browser/compare/2.2.13...2.2.14
 [2.2.13]: https://github.com/lucatume/wp-browser/compare/2.2.12...2.2.13
 [2.2.12]: https://github.com/lucatume/wp-browser/compare/2.2.11...2.2.12