Adding support for Openshift

Fix dbCount in cluster mode

Add cluster tests

only pad db key counts when running extractInfoMetrics() the first time

Move  location of redisgo

Bump redigo to 2.0.0 for new paths

set default db_keys & db_keys_expiring value to 0 for all available databases

update Gopkg.toml, use new version of dep, update vendored files

on CONFIG error log Debugf() only

update build instructions

A couple of tweaks

adding a few more client and network metrics

Add slave offset metrics

Update glide.yaml