Does not work in eu-west-2

[jacobtomlinson]

When running s3touch in the new London region I get the following error

InvalidRequest: The authorization mechanism you have provided is not supported. Please use AWS4-HMAC-SHA256.

This appears to be caused by using a legacy authentication method which is only supported in S3 regions that were launched pre 2014.

http://stackoverflow.com/questions/26533245/the-authorization-mechanism-you-have-provided-is-not-supported-please-use-aws4