Deleting users doesn't always work

[djmitche]

I noticed this while testing #246, but this occurs before that patch is landed, too.

Trying to delete a user sometimes results in a 400 from the backend which results in a JS error in the console. I don't see any additional useful logging in papertrail.

[djmitche]

This appears to happen on the second attempt to delete a user without reloading, and is due to the CSRF token not being refreshed. Also, the errorMessage function isn't defined, so no error message is shown to the user.