Use alphagov port of puppet-redis

![](http://37.media.tumblr.com/2b34eb7725b4ab426fec50311f4aa527/tumblr_n3gmnsKkgV1s2yegdo1_400.gif)
- first part of ongoing work relating to https://www.pivotaltracker.com/story/show/68978464
- Should fix errors relating to deprecated variable lookups