"Number Set" and "String Set" need to be supported

[jwchang0206]

I have looked around in "lib" folder files and found that

there are only supports for "String" and "Number"

Since DynamoDB supports data type of Sets..

"Number Set" and "String Set" need to be supported :)

[tglines]

As per Jed's response here:

http://news.ycombinator.com/item?id=4249203

I'll be doing a bit of changing things around (including adding sets) ... thanks for the issue.