mxcl/homebrew — pull request #14114 by victortrac (2012-08-10 19:18:19+00:00)
Title: Adding in required instructions to get aws-cfn-tools to work.

The formula for aws-cfn-tools requires an additional manual step of creating a credentials file before the tools will work.

I'm not sure if this is the proper way of adding in the additional caveat, but it works.