Loading DoctrineFixturesBundle in dev enveroment

Now DoctrineFixturesBundle installs only in dev.
It in exists require-dev section composer.json file.
If we run ```composer.phar install --no-dev```, we will get error:
PHP Fatal error:  Class 'Doctrine\Bundle\FixturesBundle\DoctrineFixturesBundle' not found in ...app/AppKernel.php