Add flags for managing profiles

[jacobbednarz]

Sometimes we want to use cf-vault programmatically or in automation and the processes can't handle the interactive steps. To allow using it in this fashion, we can expose the options via CLI flags.

• add
  • email
  • authentication-value
• exec
  • new options from Introduce short lived tokens #20 (session-ttl, permission-groups, resources, etc)

As a part of this, we need to establish and document a hierarchy of overrides. I.e config < env < flags where the last one in the chain is the value. IIRC, cobra/viper has this built-in and we can take advantage of it.

[simpsora]

Tangentially related, it would be cool to list the supported values for --profile-template.

[jacobbednarz]

We could do. For now, we're relying on the documentation at https://github.com/jacobbednarz/cf-vault#predefined-short-lived-token-policies