Switch jessevdk/go-flags for spf13/cobra

[chrisgilmerproj]

The primary change here is to use spf13/cobra as the CLI backend for this utility, similar to other tools Truss maintains.

This is a breaking change and requires a new release - but a release will not be cut after this PR is merged, more changes are needed.

Additionally:

• Sets up subcommands for: completion, help, version and puts the original functionality under setup subcommand
• Modifies the --role flag to be --iam-role for clarity
• Modifies the --profile flag to be --aws-profile for clarity
• Puts the environment variable AWS_VAULT_KEYCHAIN_NAME into a flag named --aws-vault-keychain-name.
• Uses a new logger for all output instead of the default log. This will help disambiguate the output from aws-vault golang libs (and other libs) and the logging for this code.
• Some small copy changes to make the output of the command more readable

Addresses these Pivotal stories:

• Bug: Env vars not working
• Story: Cleanup script logging

[chrisgilmerproj]

For testing I used this script to set up a new AWS user. It proved to do exactly what was expected. Try these commands:

go run ./cmd/ setup --iam-user cgilmer-delete-me --iam-role engineer --aws-profile delete-id --aws-account-id REDACTED

or

make bin/setup-new-aws-user
bin/setup-new-aws-user help
bin/setup-new-aws-user version
bin/setup-new-aws-user setup --iam-user cgilmer-delete-me --iam-role engineer --aws-profile delete-id --aws-account-id REDACTED

[eeeady]

Generally looks good to me. Have an inline comment on something I found using the docs.

I might ask that you geta 2nd review since my golang is probably not the best.