add ability to hard delete users

[theandrewykim]

For #396

[jonnyom]

This looks good to me 👍

[choran]

looks good @theandrewykim nice work.
It might be a little confusing to have a delete and a hard delete now that the terms are archive and permanently delete on the API. If you have time would it be possible to add a wrapper to alias the current delete so that we can use archive instead of delete?
Also, if you have the code you used here could you add an example for the readme?
If you dont have the time we can merge this and I can open a backlog item to alias it and update the readme