Have Leverage help with configuring Kubeconfig and refreshing credentials

[diego-ojeda-binbash]

Describe the Feature

Proposed commands:

1. leverage eks configure
   1. Should discover all clusters
   2. Provide a wizard to list cluster and configure them
2. leverage eks refresh-credentials
   1. Should discover all clusters
   2. Move to the right cluster path and run leverage tf refresh-credentials

The above could later on be integrated with Kube config files so the leverage eks refresh-credentials is called transparently.