Interactive mode

[pckilgore]

With MFA, we can't just roll keys programmatically (or can we? 1Password API? I hope not).

Need a different strategy.

MVP:

• Don't even hit the AWS API if we detect MFA characteristics in profile (but still bail and warn).
• Add interactive mode that asks for a code then does the thing

Other thoughts:

• Print a notice to terminal on start if keys closing on some sort of date?
• How do we store max_key_age somewhere? In profile? In XDA_CONFIG?