improvements to log collector kubeadm collection

[gnuninu]

I am about to submit a PR to address the following improvements to the kubeadm collection.

• Removed collection of cluster-info dump to avoid gathering of sensible data

• reduced collection of logs in /var/log/pods/ to only system clusters namespaces

• fixed user variable when ran with sudo

• a custom kubeconfig file location can now be specified with the -k switch