Merge pull request #561 from rezonanc/suggestion/php_redis_admin

Add phpRedisAdmin

README.md

 * [PHP Queue](https://github.com/CoderKungfu/php-queue) - An application for managing queueing backends.
 * [MailCatcher](https://github.com/sj26/mailcatcher) - A web tool for capturing and viewing emails.
 * [Cachet](https://github.com/cachethq/cachet) - The open source status page system.
+* [phpRedisAdmin](https://github.com/ErikDubbelboer/phpRedisAdmin) - A simple web interface to manage [Redis](http://redis.io/) databases.
 
 ## Infrastructure
 *Infrastructure for providing PHP applications and services.*