drrb/cfoo — pull request #4 by agperson (2014-09-23 13:05:53+00:00)
Title: Allow empty string to intrinsic function !GetAZs

As per spec !GetAZs "" is allowed and equivalent to !GetAZs $(AWS::Region)

http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/intrinsic-function-reference-getavailabilityzones.html