Feature/1519 upstream redis

Replacing forked redis and redis-ha charts with current upstream redis chart.

Couple of things to insure that this update has the least amount of impact on existing and new installs of the chart.

• Password is seen by new Redis install
• k8s Service names work for HA and single nodes
• Upgrade from single node to HA works
• Same persistent store is used after upgrade
  • Seems that there may be additional persistent stores being created (i.e. gitlab/data-gl-redis-server-0 vs. gitlab/redis-data-gl-redis-master-0)
• Update documentation
• When using sentinel support, the service name needs to be configured

Closes #1519 (closed)