Merge pull request #582 from ReadmeCritic/patch-1

Update PhpMetrics link

README.md

 * [PHP Analyser](https://github.com/scrutinizer-ci/php-analyzer) - A library for analysing PHP code to find bugs and errors.
 * [PHP CS Fixer](https://github.com/FriendsOfPHP/PHP-CS-Fixer) - A coding standards fixer library.
 * [PHP Manipulator](https://github.com/schmittjoh/php-manipulator) - A library for analysing and modifying PHP Source Code.
-* [PHP Metrics](https://github.com/Halleck45/PhpMetrics) - A static metric library.
+* [PHP Metrics](https://github.com/phpmetrics/PhpMetrics) - A static metric library.
 * [PHP Refactoring Browser](https://github.com/QafooLabs/php-refactoring-browser) - A command line utility for refactoring PHP code.
 * [PHP Semantic Versioning Checker](https://github.com/tomzx/php-semver-checker) - A command line utility that compares two source sets and determines the appropriate semantic versioning to apply.
 * [UBench](https://github.com/devster/ubench) - A simple micro benchmark library.