Remove warnings that are no longer relevant (#1797)
Remove warnings that are no longer relevant (#1797)

Remove warning that prior to Istio 0.8 Helm was unstable.
Since we are on 1.0, and can expect people to upgrade from 0.8,
this warning doesn't seem relevant.

Also, Helm upgrade from 0.8 to 1.0 has been validated.  Also
remove that warning.
istio/istio.io,linsun/istio.github.io,istio/istio.io,linsun/istio.github.io,geeknoid/istio.github.io,linsun/istio.github.io,geeknoid/istio.github.io,istio/istio.io,geeknoid/istio.github.io,istio/istio.io,linsun/istio.github.io,geeknoid/istio.github.io,istio/istio.io,istio/istio.io,geeknoid/istio.github.io,linsun/istio.github.io,istio/istio.io