Install behat upon new profile creation

[amitaibu]

Currently on a clean installation your Behat isn't up and running. You need to download composer and install the packages.

cd @skeleton/behat
curl -sS https://getcomposer.org/installer | php
php composer.phar install
cd -

In fact, if you would ask for the the URL of the site in the process, you could execute the single behat test in the end of the profile creation in order to validate all is working.