Merge pull request #479 from micheleorselli/adds_tideways

[debugging and profiling] tideways.io

README.md

 * [PHP Debug Bar](http://phpdebugbar.com/) - A debugging toolbar.
 * [PHPBench](https://github.com/phpbench/phpbench) - A benchmarking Framework.
 * [PHPDBG](http://phpdbg.com/) - An interactive PHP debugger.
+* [Tideways.io](https://tideways.io/) - Monitoring and profiling tool
 * [Tracy](https://github.com/nette/tracy) - A simple error detection, logging and time measuring library.
 * [xDebug](https://github.com/xdebug/xdebug) - A debug and profile tool for PHP.
 * [XHProf](https://github.com/phacility/xhprof) - A profiling tool originally developed by Facebook.