Log Output should be saved to file automatically

[danbudris]

What would you like to be added: when running the eks-a CLI, log output should be automatically output to file as well as to stdout

Why is this needed: in cases where an SSH connection to a mgmt machine is terminated, but the CLI is still running, there is no way to recover the log output in a reliable way; we should set up a way where this can be recovered more easily.

[vivek-koppuru]

It would be beneficial to have this also always output verbose logs so that we have that output when a user doesn't specify verbose logging.