Fix PagedResult.Next() returning true if there are 0 results.

If the first page has 0 results, PagedResult.Next() still has
a return value of 'true' the first time it's called, but .Scan()
will error if it's called because there are no results.
Merge pull request #3 from Clever/fix-no-results-bug

Fix PagedResult.Next() returning true if there are 0 results.