gk-deploy: Use check() for namespace
gk-deploy: Use check() for namespace

In cases where the kubelet service has been very recently started,
Kubernetes may report that there is no namespace while it's spinning up.
This introduces a short wait to let Kube come up, but not too long as we
still want to know if the namespace actually doesn't exist.

Signed-off-by: Jose A. Rivera <2a0958b6fecb909a38a254361e8d9708c4487d67@redhat.com>

gluster/gluster-kubernetes,gluster/gluster-kubernetes