NoRegionError: You must specify a region. causing Altimeter to crash on use.

[dmoore247]

This line of code causes Altimeter to crash upon first use.
s3_client = boto3.client("s3") throws NoRegionError: You must specify a region. error because the region parameter is not specified and the AWS_DEFAULT_REGION environment variable wasn't specified.

Suggest either adding region parameter to the call based on what's in the config file or pick a region by default, or tell user to set AWS_DEFAULT_REGION and/or update documentation.

[jbmchuck]

Thanks for the report - the entrypoint bash script has been updated to detect this as of 6.4.18 - https://github.com/tableau/altimeter/pull/207/files#diff-e5f16e411360ad8e6f528dea8207537a71c2dca1869926d152c00017bde3ff4d