Update redis / sentinel init script templates to create PIDDIR

[zbal]

Similarly to Ubuntu, /var/run or /run on CentOS 7 is a tmpfs based file system and get emptied on reboot. Adding the creation step of that PIDDIR folder in the init scripts.

[DavidWittman]

@zbal Can you remove the commit to add Redis to the path? Since the issues have been addressed in the alternatives module, I can explore adding Redis to the path again that way.