aws/aws-cli — pull request #475 by jamesls (2013-11-06 20:33:50+00:00)
Title: Add a note about aws configure with user has no credentials

This means we have to check for credentials before we call
get_endpoint(), because it can raise an exception about region
not being specified.

Error message now looks like this:

```
$ aws ec2 describe-instances
Unable to locate credentials. You can configure credentials by running "aws configure".
```