replacing the obsolete repository (#32)

vars/Ubuntu.yml

@@ -3,7 +3,7 @@
 # Defaults are defined in vars/default.yml
 
 # redis server properties
-redis_pkg_repo: 'ppa:rwky/redis'
+redis_pkg_repo: 'ppa:chris-lea/redis-server'
 redis_pkg_name: redis-server
 
 # Sensu/Uchiwa user/group/service properties