Update PHP 5.4 to 5.4.35
Update PHP 5.5 to 5.5.20
Update PHP 5.6 to 5.6.4
README.md: fix Homebrew link.
Update php55-redis to 2.2.6

The repository moved from https://github.com/nicolasff/phpredis to https://github.com/phpredis/phpredis
php55-redis: add 2.2.6 bottle.