CHANGELOG documents PR for new test case output format

Author: johnkary

CHANGELOG.md

@@ -7,6 +7,7 @@ https://github.com/johnkary/phpunit-speedtrap/commit/XXX where XXX is the commit
 ## 4.0.0 (2021-05-03)
 
 * Changelog ([`v3.3.0...v.4.0.0`](https://github.com/johnkary/phpunit-speedtrap/compare/v3.3.0...v4.0.0))
+* [PR #81](https://github.com/johnkary/phpunit-speedtrap/pull/81) Reformat slow test case output for compatibility with PHPUnit --filter option
 * [PR #82](https://github.com/johnkary/phpunit-speedtrap/pull/82) New option `stopOnSlow` stops execution upon first slow test. Default: false.
 * [PR #84](https://github.com/johnkary/phpunit-speedtrap/pull/84) New annotation option `@slowThreshold 0` disables checks for individual tests.