Some improvements on the PHP kata

Hi,

Would like to introduce some improvements on the PHP kata. Yesterday I was playing with it and saw some improvement points.

#### PHP Standards Recommendation
I've rewritten the initial code in order to be complaint with the *PHP Standards Recommendations* (PSRs). The list of the recommendations and it's details can be found here: **http://php-fig.org**

#### Composer support
Until now, to perform the kata you depend on system packages (PHPUnit installed through the PEAR repository). Recently, PHPUnit has deprecated the installation through PEAR, so I've added composer support in order to handle the dependencies without relying on system packages.

In addition with the introduction of Composer, if the newly created classes follow the PSR-0, a PSR for autoloading classes, they can be autoloaded without the need to require them explicitly on the code, so then there's no more need to have a dedicated PHPUnit bootstrap file.

And to end with composer improvement, If you would want to register in the future the kata on packagist (a repository of PHP packages that's having a huge impact on the PHP community) you could do it easily thanks to the *composer.json* file.

**https://packagist.org/**

Hope that you find it useful!
Christian.