Handle limit for query requests to dynamo

The supplied task cases show scenario's where previously a 400 error would be returned due to limit reaching zero.  

Here is the message I saw in the stack trace:
ValidationException: ValidationException: 400 Bad Request
{u'message': u"1 validation error detected: Value '0' at 'limit' failed to satisfy constraint: Member must have value greater than or equal to 1", u'__type': u'com.amazon.coral.validate#ValidationException'}