fix(registry): Use cache host and port from confd
fix(registry): Use cache host and port from confd

The registry was crashing when trying to read cache
settings from unset environment variables.
confd is now also population those settings.

I also disabled the LRU cache as this requires a redis in LRU mode:
http://redis.io/topics/config

deis/workflow,deis/workflow,deis/workflow