json schema for meta data table not explicit enough

[isichei]

Boto throwing error:

ValidationException: An error occurred (ValidationException) when calling the CreateTable operation: 2 validation errors detected: 
...
at 'table.storageDescriptor.columns.5.member.comment' failed to satisfy constraint: Member must satisfy regular expression pattern: [\u0020-\uD7FF\uE000-\uFFFD\uD800\uDC00-\uDBFF\uDFFF\t]*;

Should update schemas to catch this error further upstream.