add region to sqs_launcher

[bsda]

This allows sqs_launcher to use the same region configured in the listener

[jegesh]

I'm concerned that your modifications force a valid region name to be passed in the launcher constructor, which breaks the API. Please add a check if the region is set by config file or env vars, then use that value when the region is not passed in the constructor. Unless you know that the aws code already does that when given an empty string. In any case I think setting the default value to None makes more sense than an empty string.

[posix4e]

I think we can close this out