step 9: install redis (redis.io store)

Installation of redis on CentOS 6:
Redis (the redis.io key-value store) is available in the remy repo which depends on the epel repo:
If you didn't already previously add the remi repo to your repositories then follow the following step to do so.
I wanted the remi repo "Enterprise Linux 6 (with EPEL)" package, you may have to use another one depending on your OS and version, i used centos6 and therefore choosed to use the following commands: