Remove mention of Packagist.
Remove mention of Packagist.

stefanotorresi/php-fig.github.com,php-fig/php-fig.github.com,stefanotorresi/php-fig.github.com,php-fig/php-fig.github.com,php-fig/php-fig.github.com,stefanotorresi/php-fig.github.com,stefanotorresi/php-fig.github.com,php-fig/php-fig.github.com,stefanotorresi/php-fig.github.com,php-fig/php-fig.github.com