switch footer version to 0.3.0 (#782)
switch footer version to 0.3.0 (#782)

we already have changed several doc (auth) with instructions that only work for 0.3
geeknoid/istio.github.io,geeknoid/istio.github.io,jasminejaksic/istio.github.io,istio/istio.io,jasminejaksic/istio.github.io,geeknoid/istio.github.io,ZackButcher/istio.github.io,linsun/istio.github.io,istio/istio.io,geeknoid/istio.github.io,istio/istio.io,istio/istio.io,linsun/istio.github.io,ZackButcher/istio.github.io,linsun/istio.github.io,linsun/istio.github.io,istio/istio.io,ZackButcher/istio.github.io,ZackButcher/istio.github.io,jasminejaksic/istio.github.io,jasminejaksic/istio.github.io,istio/istio.io,geeknoid/istio.github.io,linsun/istio.github.io,istio/istio.io