Tarmak export logs command

[JoshVanL]

/kind feature

What happened:
Often when debugging with someone remotely it is difficult to ensure all logs of interested are collected. This can lead to missing something or increasing the debug loop time to find the problem/solution.

What you expected to happen:
Tarmak should provide a command that goes and fetches the logs which can then be bundled together in a consistent way. This should be done by SSHing into all relevant instances, grabbing journald into a file. Bundle all these files into a tar ball for the user. Exports we should support (not complete):
tarmak cluster logs vault - includes consul cluster and helpers
tarmak cluster logs etcd - includes backups etc
tarmak cluster logs worker - kubelet etc..
tarmak cluster logs master - api server etc..

/assign