Removed magix execution of composer.

Some work for #108. 

As discussed I wanted to add a composer `post-install-cmd` as described inside the composer [scripts documentation](http://getcomposer.org/doc/articles/scripts.md). As `console phpci:install` does require interactive input this [does not seem to be possible](http://webcache.googleusercontent.com/search?output=search&sclient=psy-ab&q=cache%3Ahttp%3A%2F%2Fstackoverflow.com%2Fquestions%2F15008095%2Fcomposer-post-install-cmd-script-to-run-interactive-cli-php-command&oq=cache%3Ahttp%3A%2F%2Fstackoverflow.com%2Fquestions%2F15008095%2Fcomposer-post-install-cmd-script-to-run-interactive-cli-php-command&gs_l=hp.3..0l4.869.2470.0.3201.9.9.0.0.0.0.69.295.5.5.0....4...1c.1j2.23.psy-ab..4.5.280.mVHBlhhCook&pbx=1).

Installation process would require one additional step as described in the updated [README](README.md). Is this ok?