Awsume does not export the AWS region variables based on a profile

[hauboldj]

In my ~/.aws/config file I have something like this

[profile someAccount-somerole]
region = us-west-2
role_arn = arn:aws:iam::123412341234:role/someRole
mfa_serial = arn:aws:iam::432143214321:mfa/jhaubold
source_profile = iam-jhaubold

When I awsume this profile the AWS_REGION and AWS_DEFAULT_REGION variables are set to us-east-1 not us-west-2 as expected. I say as expected because this was the previous behavior of awsume.