Boolean values do not round-trip through Xlsx

[ajparsons]

Something I ran into trying to round-trip BODS data was that if the JSON originally had a boolean value, putting this into and then out of XLSX converted it to a string (true > 'true'). It looks good in the XLSX, so I think this is happening when it is converted back.

[jpmckinney]

@ajparsons I'm curious about your use case for round-tripping? In my experience, publishers might prepare data in tabular format, then convert to JSON; or users might download JSON data, then convert to CSV. I haven't actually heard a real use case for round-tripping (except some internal development needs, though I know round-tripping is a main feature/constraint of Flatten Tool), so I'm curious to hear more.