* Add OpenEBS v0.8 Chart

OpenEBS 0.8 add support for:
- cStor Storage Engine
- Further enhancements to Jiva Storage Engine
- Ability to send anonymous usage statistics
- More flexible Storage Policy declarations for Storage Engines
  via CAS Templates
- Automated setting up of default storage classes.

This release also removes the bundling of Prometheus and Grafana
and is limited to installing only OpenEBS core components.
Signed-off-by: kmova <kiran.mova@openebs.io>