v0.6.0

Changelog

• 8d42ae2 Add instance IP address to list output (#63)
• e964535 Add shell subcommand (#62)
• 3bda077 Fetch IP only for running instances (#65)
• 1859721 Fix the permission of Kubeconfig (#66)
• b7f8a36 Fixes the KUBECONFIG file permission (#64)