WL-2962 If forename/lastname is empty reject it.

We were seeing an instructor fail to be added because TII rejected it so although we check for we don't check for empty strings.
WL-2962 Log any failures from role swap.

I'm not sure this is the problem, but it should help debug where it's going wrong.
Merge pull request #6 from ox-it/WL-2962

WL-2962