Add ability to use non-default profile

[asokolsky]

From what I understand, cloud-nuke currently uses default aws profile. It would be nice to have this fact documented. I rely on multiple accounts to structure AWS resources. It would be much appreciated if cloud-nuke would support command line options similar to aws to specify profile, e.g. cloud-nuke --profile foo-bar aws

[yorinasub17]

This is currently not supported via CLI option, but open to a PR to add it in! With that said, see https://github.com/gruntwork-io/cloud-nuke/issues/49 for workaround.

[james00012]

Closing this issue as we have answer for this already.