Feature: Use redis instead of node memory
Feature: optional redis or memory storage

How tokens are stored can now be switched with to either in-memory
or redis. Redis support allows Hollaback to scale horizontally
while the in-memory storage allows for simple, single node
deployments.
Fix: Broken path to TokenStore library
Use environment variables for remote redis

Optionally use environment variables to connect to a remote redis
server.

Throw an error if the redis config 'notify-keyspace-events' is not AKE.
Merge remote-tracking branch 'origin/feature/redis-integration'