provide a way to refresh credentials

[sirdarckcat]

error: You must be logged in to the server (Unauthorized)

[sirdarckcat]

also, we shouldn't hide the output of the gcloud commands, as they sometimes ask for auth.

[sirdarckcat]

kctf config load (name)

works for reauth but it's not always working because we hide the stdout

[sirdarckcat]

this is really annoying :P