Add test for main.awsProfile() where profile name is empty string and AWS_DEFAULT_PROFILE env var is set.
Add test for main.awsProfile() where profile name is empty string and
AWS_DEFAULT_PROFILE env var is set.

Result expected is that if AWS_DEFAULT_PROFILE is a vaild profile, those
values will be returned

mmmorris1975/aws-runas,mmmorris1975/aws-runas,mmmorris1975/aws-runas,mmmorris1975/go-aws-runas,mmmorris1975/aws-runas,mmmorris1975/aws-runas